Spyder Phyton 6.1.3

What's new in this version:

New features:
- Allow to reconnect to remote kernels after the connection is lost
- Add ability to explore objects that depend on custom library code to the Variable Explorer

Important fixes:
- Fix memory leak on Linux when getting user's environment variables
- Fix several issues with the auto-update process of the standalone installers
- Fix segfault on closing with PyQt6
- Fix errors when creating new remote connections if credentials are wrong
- Finish fixing and improving docstrings for modules under spyder.api

API changes:
- Add sig_update_performed signal to Update manager plugin
- All public and most private APIs in spyder.api now have comprehensive docstrings and type hints with descriptions, parameters, returns and raises, and are thoroughly rewritten for correctness, clarity and proper formatting. They are also now fully built and richly rendered on the new Spyder developer docs site.

spyder.api.plugin_registration modules:
- The mixins module, containing the mixin used internally for handling the @on_plugin_available and @on_plugin_teardown decorators in the SpyderPluginV2 class, is now documented as pending deprecation as a public module, will become an alias of a private _mixins module and issue a DeprecationWarning in Spyder 6.2, and have the public alias be removed in Spyder 7.0. It is a private implementation detail that wasn't designed or intended to be used directly by external code; plugins access its functionality through the SpyderPluginV2 class instead.
- The registry module's vestigial SpyderPluginRegistry.old_plugins attribute, originally added in Spyder 5 to list legacy Spyder 4 plugins, has been removed. It was mistakenly left over when Spyder 6 fully dropped support for Spyder 4 plugins, which never actually functioned as intended and should be updated to support modern Spyder 5+ plugins instead.
- In the registry module's SpyderPluginRegistry class, setters for the all_internal_plugins (set_all_internal_plugins()), all_external_plugins (set_all_external_plugins()) and main (set_main()) instance attributes are now documented as pending deprecation, will raise a DeprecationWarning in Spyder 6.2, and will be removed in Spyder 7.0. Set the attributes directly instead.
- In the registry.SpyderPluginRegistry class' register_plugin() method, passing arbitrary *args and **kwargs is now documented as pending deprecation, will raise a DeprecationWarning in Spyder 6.2 and will be removed in Spyder 7.0. This was only needed for backward compatibility before the Editor plugin was migrated in Spyder 6 to the new plugin API introduced in Spyder 5.

spyder.api.plugins modules:
- Importing from the enum and new_api modules is now documented as pending deprecation. In Spyder 6.2, they will be renamed to the private _enum and _api modules, respectively, with the original names becoming aliases raising a DeprecationWarning on import, that will be removed in Spyder 7.0. They should be imported from their canonical location, the top-level spyder.api.plugins module, instead.
- The SpyderPluginV2's main instance attribute is now a property, to reduce duplication with the identically-valued _main attribute.
- SpyderPluginV2's _added_toolbars and _actions private attributes have been removed, as they are not used at least in Spyder 6 and above.
- Obsolete checks/warnings for SpyderPluginV2's removed register() and unregister() methods have been removed, as they have been unsupported since Spyder 5.1/5.2 and any code still using them is already broken. The respective on_initialize() and on_close() methods should be used instead.

spyder.api.widgets modules:
- In the mixins module's SpyderActionMixin.update_actions() method, remove the spurious leftover options parameter that does nothing, and is inconsistent and incompatible with all its actual current usage. As this is an abstract method and none of its implementations include it, any plugin code that does will already raise an error at runtime.
- In the menus and toolbars modules, the SpyderMenuProxyStyle and ToolbarStyle proxy style classes are now documented as pending deprecation. In Spyder 6.2, they will be renamed to the private _SpyderMenuProxyStyle and _ToolbarStyle classes, respectively, with the original names becoming aliases raising a DeprecationWarning on use, that will be removed in Spyder 7.0. They were never intended to be used directly by plugins.
- In the toolbars module, ToolbarStyle.pixelMetric() now correctly raises a SpyderAPIError (instead of silently not working as intended save for a spurious print() call) if the TYPE class attribute is not set to one of the two valid values, "Application" or "MainWindow". Additionally, using SpyderToolbar directly rather than its ApplicationToolbar and MainWidgetToolbar subclasses is now documented as formally discouraged so their respective styling will be applied.
- In the toolbars module, the ToolTipFilter class is now correctly underscored as private, as it is only for internal use handling Qt events by a private attribute of the SpyderToolbar class.

Fixed:
- NotImplementedError when trying to display Pandas DataFrame in Variable Explorer
- KeyError in lsp_mixin when using quick-lint-js Javascript LSP
- TypeError when closing project while it is loading
- Variable explorer raises error on a np.datetime64 object
- Scripts on remote server cannot be opened through Files pane
- Find in files displaying "string not found" while search is still running
- Update Spyder with pop up useless if one has a specific environment
- Numpad-Enter does not trigger search inside search box
- Error when updating Spyder in Anaconda as if it were standalone installer
- PermissionDenied error when remote connection credentials are wrong
- Updating Spyder obliterates conda environment
- Small refactor in Client.init to support custom ShellWidget
- Last run file becomes active when running last file rather than keeping active file current
- Spyder segfaults when closing with PyQt6
- TypeError in Update manager worker
- Annotation markers shown incorrectly and disabling option hides editor side pane
- Spyder consumes all RAM at startup on Linux, leading to whole system crash
- Two Spyder icons on Windows taskbar (regression?)
- Deselecting "Stop debugging on first line of files without breakpoints" ignores breakpoints in other files
- Opening a PyVista object can cause the error report dialog to be shown
- Retrieving the value of a variable in the Variable Explorer depends on how a module is imported