[rcore][rgfw] No key release on focus loss

[M374LX]

With the RGFW backend, when the window loses focus while a key is still being held, the program behaves as if the key were still being held, even if it is actually released after the focus loss.

The issue is not present in the GLFW and SDL backends.

[raysan5]

@M374LX could you send a PR to address this issue?

[M374LX]

@ColleagueRiley Apparently, GLFW and SDL automatically generate a key release event for each key being held when the window loses focus, which RGFW does not. Do you think RGFW should do the same?

https://github.com/glfw/glfw/blob/e7ea71be039836da3a98cea55ae5569cb5eb885c/src/window.c#L43

[ColleagueRiley]

Although the solution seems sketchy, I think it's worth implementing. Sadly I don't think there is a better solution.

This issue should probably be moved over to the RGFW repo.

[M374LX]

Here it is: ColleagueRiley/RGFW#171.