refactor: Add more checks to pre-commit

Updated existing pre-commit hooks and added some new hooks:

- Remove trailing whitespace
- Ensure every non-empty file ends with a new line
- Check YAML file validity
- Prevent adding large files
- Ensure any scripts with shebangs are executable

Added a GitHub action to run pre-commit on every commit. Removed any
existing actions which duplicate pre-commit.

Ran pre-commit on the codebase.

app/boards/shields/tidbit/tidbit.keymap

@@ -21,7 +21,7 @@
 
 	keymap {
 		compatible = "zmk,keymap";
-		
+
 		default_layer {
 			bindings = <
 								&kp KP_NUMLOCK  &kp KP_ASTERISK &kp KP_MINUS