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/core-coverage.yml

@@ -1,35 +1,35 @@
 board:
-- nice_nano_v2
-- nrfmicro_13
-- proton_c
+  - nice_nano_v2
+  - nrfmicro_13
+  - proton_c
 shield:
-- corne_left
-- corne_right
-- romac
-- settings_reset
-- tidbit
+  - corne_left
+  - corne_right
+  - romac
+  - settings_reset
+  - tidbit
 include:
-- board: bdn9_rev2
-- board: nice60
-- board: seeeduino_xiao_ble
-  shield: hummingbird
-- board: nrf52840_m2
-  shield: m60
-- board: planck_rev6
-- board: proton_c
-  shield: clueboard_california
-- board: nice_nano_v2
-  shield: kyria_left
-  cmake-args: "-DCONFIG_ZMK_DISPLAY=y"
-  nickname: "display"
-- board: nice_nano_v2
-  shield: kyria_right
-  cmake-args: "-DCONFIG_ZMK_DISPLAY=y"
-  nickname: "display"
-- board: nice_nano
-  shield: romac_plus
-  cmake-args: "-DCONFIG_ZMK_RGB_UNDERGLOW=y -DCONFIG_WS2812_STRIP=y"
-  nickname: "underglow"
-- board: nice_nano_v2
-  shield: lily58_left nice_view_adapter nice_view
-  nickname: "niceview"
+  - board: bdn9_rev2
+  - board: nice60
+  - board: seeeduino_xiao_ble
+    shield: hummingbird
+  - board: nrf52840_m2
+    shield: m60
+  - board: planck_rev6
+  - board: proton_c
+    shield: clueboard_california
+  - board: nice_nano_v2
+    shield: kyria_left
+    cmake-args: "-DCONFIG_ZMK_DISPLAY=y"
+    nickname: "display"
+  - board: nice_nano_v2
+    shield: kyria_right
+    cmake-args: "-DCONFIG_ZMK_DISPLAY=y"
+    nickname: "display"
+  - board: nice_nano
+    shield: romac_plus
+    cmake-args: "-DCONFIG_ZMK_RGB_UNDERGLOW=y -DCONFIG_WS2812_STRIP=y"
+    nickname: "underglow"
+  - board: nice_nano_v2
+    shield: lily58_left nice_view_adapter nice_view
+    nickname: "niceview"