Use the commit sha to be stricter with pinning

Author: myftija

.github/workflows/vouch-check-pr.yml

@@ -13,7 +13,7 @@ jobs:
   check-pr:
     runs-on: ubuntu-latest
     steps:
-      - uses: mitchellh/vouch/action/check-pr@v1.4.2
+      - uses: mitchellh/vouch/action/check-pr@c6d80ead49839655b61b422700b7a3bc9d0804a9 # v1.4.2
         with:
           pr-number: ${{ github.event.pull_request.number }}
           auto-close: true

.github/workflows/vouch-manage-by-issue.yml

@@ -16,7 +16,7 @@ jobs:
       contains(github.event.comment.body, 'denounce') ||
       contains(github.event.comment.body, 'unvouch')
     steps:
-      - uses: mitchellh/vouch/action/manage-by-issue@v1.4.2
+      - uses: mitchellh/vouch/action/manage-by-issue@c6d80ead49839655b61b422700b7a3bc9d0804a9 # v1.4.2
         with:
           comment-id: ${{ github.event.comment.id }}
           issue-id: ${{ github.event.issue.number }}