Pin prek-action to commit SHA (#378)

Closes #36

Co-authored-by: Oleg Gusakov <oleg@render.com>
GitOrigin-RevId: 7cf54938bea3d8f59020d1c36b513e4613848157

Author: oleg-render

.github/workflows/prek.yaml

@@ -29,6 +29,6 @@ jobs:
           go install mvdan.cc/sh/v3/cmd/shfmt@latest
           echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
 
-      - uses: j178/prek-action@v1
+      - uses: j178/prek-action@0bb87d7f00b0c99306c8bcb8b8beba1eb581c037  # v1 (v1.1.1)
         with:
           extra-args: '--all-files --verbose'