Fix Input.is_action_just_pressed flicker on joypad axes

[ErezShahaf]

Fixes #81975
Pressed tick assignments were in the wrong scope, ended up updating pressed_frame even when it shouldn't and therefore the just_press would return true every time that the strength changes and not only when there's a new press.

[Sauermann]

With the exception of the comments, the changes are looking good. Only reviewed code, but didn't test it.

[Calinou]

Tested locally, this is how the MRP linked in #81170 (comment) behaves:

master 42425ba

simplescreenrecorder-2023-10-12_20.08.24.mp4

This PR

simplescreenrecorder-2023-10-12_20.06.29.mp4

I still notice two issues:

• On both master and this PR, the strength of the "Both" action (an action that is activated by both keyboard and gamepad events) remains on 100% when the keyboard is released if the gamepad is held still above 0%.
• Controller strength sometimes flickers wildly, but I don't know exactly why. This may be related to mouse movement (I'm using a wired DualSense which has a touchpad that moves the mouse when you touch it).

[Eoin-ONeill-Yokai]

Once @Sauermann 's issues are resolved, I think this is good to go.

I've tested it with a few devices on my end and the axis "just_pressed" flag triggers appropriately only when entering the deadzone. Additionally, "just_released" works as expected as well.

I didn't observe any flickering inputs on my end compared to @Calinou 's observations. Having said that, I'm using mostly DS4, 8BitDo and Xbox Series X Controllers. The Series X controller on linux seems to register inputs twice still (looking into a solution to this still, if possible) but otherwise it seemed to behave akin to how master behaves.

[akien-mga]

Please remember to squash the commits while addressing the code review comments. See PR workflow for instructions.

[akien-mga]

I squashed the commits and addressed the review comments myself.

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉