[CI] hash all build.yml and west.yml files

.gitea/workflows/build.yml

@@ -31,9 +31,9 @@ jobs:
         id: hash-west
         run: |
           FILE_PATH=zephyr/west.yml
-          HASH=$(sha256sum $FILE_PATH | head -c 64)
+          HASH=$(sha256sum <(find . -name build.yml -o -name west.yml -type f -exec sha256sum \; | sort) | head -c 64)
           echo "hash=$HASH" >> "$GITHUB_OUTPUT"
-          echo "computed hash: $HASH $FILE_PATH"
+          echo "computed hash: $HASH"
 
       - name: Cache west modules
         uses: actions/cache@v3
@@ -45,6 +45,7 @@ jobs:
             tools/
             zephyr/
             bootloader/
+            zmk/
           key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ steps.hash-west.outputs.hash }}
           restore-keys: |
             ${{ runner.os }}-build-${{ env.cache-name }}-