chore(deps): update reviewdog/action-shellcheck action to v1.21.0 (#399)

| datasource  | package                     | from    | to      |
| ----------- | --------------------------- | ------- | ------- |
| github-tags | reviewdog/action-shellcheck | v1.20.0 | v1.21.0 |

Author: stackable-bot

.github/workflows/pr_reviewdog.yaml

@@ -51,7 +51,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
-      - uses: reviewdog/action-shellcheck@72365a51bf6476fe952a117c3ff703eb7775e40a # v1.20.0
+      - uses: reviewdog/action-shellcheck@6e3a862f231c6895fbd335b70adef8f9243d5762 # v1.21.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
 

template/.github/workflows/pr_reviewdog.yaml

@@ -55,7 +55,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
-      - uses: reviewdog/action-shellcheck@72365a51bf6476fe952a117c3ff703eb7775e40a # v1.20.0
+      - uses: reviewdog/action-shellcheck@6e3a862f231c6895fbd335b70adef8f9243d5762 # v1.21.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}