Update prek workflow (#280)

Use j178/prek-action to install and run prek, and add Go bin
directory to PATH so shfmt is discoverable by prek hooks.

Author: metonym

.github/workflows/prek.yaml

@@ -13,25 +13,22 @@ concurrency:
 jobs:
   prek:
     name: Run prek hooks
-    runs-on: arc-runner-15cpu
+    runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Cache Go modules
-        uses: actions/cache@v4
+      - name: Set up Go
+        uses: actions/setup-go@v5
         with:
-          path: ~/.cache/go-build
-          key: ${{ runner.os }}-go-prek-${{ hashFiles('**/go.sum') }}
+          go-version: 1.25
+          cache: true
 
       - name: Install shfmt
-        run: go install mvdan.cc/sh/v3/cmd/shfmt@latest
+        run: |
+          go install mvdan.cc/sh/v3/cmd/shfmt@latest
+          echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
 
-      - name: Cache prek
-        uses: actions/cache@v4
+      - uses: j178/prek-action@v1
         with:
-          path: ~/.cache/prek
-          key: prek-${{ hashFiles('prek.toml') }}
-
-      - name: Run prek
-        run: prek run --all-files --show-diff-on-failure --verbose
+          extra-args: '--all-files --verbose'