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/eek/eek.overlay

@@ -20,7 +20,7 @@
     RC(0,9) RC(0,8) RC(0,7) RC(0,6) RC(0,5) RC(0,4) RC(0,3) RC(0,2) RC(0,1) RC(0,0)
     RC(1,9) RC(1,8) RC(1,7) RC(1,6) RC(1,5) RC(1,4) RC(1,3) RC(1,2) RC(1,1) RC(1,0)
     RC(2,9) RC(2,8) RC(2,7) RC(2,6) RC(2,5) RC(2,4) RC(2,3) RC(2,2) RC(2,1) RC(2,0)
-                    RC(3,7) RC(3,6) RC(3,5) RC(3,4) RC(3,3) RC(3,2) 
+                    RC(3,7) RC(3,6) RC(3,5) RC(3,4) RC(3,3) RC(3,2)
             >;
     };