This commit changes the keying code to deselect keyframes when inserting new keys. This has been discussed in the Animation & Rigging module meeting [1]. There is also an RCS post about that [2]. Doing this brings key creation in line with object creation, where only the newly created object is selected. There has been a previous attempt [3] to do a similar thing. ### Changes When inserting keys by pressing `I` in the viewport or choosing a keying set, all keys of the `Action` get deselected before inserting new keys. New keys are selected by default. Python RNA functions are **NOT** affected, meaning addons using those functions will not deselect any keys by default. The developer has to choose to do so. To make that easier, there is a new RNA function on the action `deselect_keys` [1]: https://devtalk.blender.org/t/2024-05-02-animation-rigging-module-meeting/34493#patches-review-decision-time-5 [2]: https://blender.community/c/rightclickselect/K0hbbc [3]: https://archive.blender.org/developer/D11623 Pull Request: https://projects.blender.org/blender/blender/pulls/121908