chore(deps): update reviewdog/action-markdownlint action to v0.20.0

| datasource  | package                       | from    | to      |
| ----------- | ----------------------------- | ------- | ------- |
| github-tags | reviewdog/action-markdownlint | v0.18.0 | v0.20.0 |

Author: stackable-bot

.github/workflows/pr_reviewdog.yaml

@@ -42,7 +42,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
-      - uses: reviewdog/action-markdownlint@5bc6ad5ba9e1250878f351bafcc7ac0a11dc050f # v0.18.0
+      - uses: reviewdog/action-markdownlint@8a1ef8f946e74c4d7119ec2489069a870b2a4e8f # v0.20.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           markdownlint_flags: '**/*(*.md|*.md.j2)'

template/.github/workflows/pr_reviewdog.yaml

@@ -46,7 +46,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
-      - uses: reviewdog/action-markdownlint@5bc6ad5ba9e1250878f351bafcc7ac0a11dc050f # v0.18.0
+      - uses: reviewdog/action-markdownlint@8a1ef8f946e74c4d7119ec2489069a870b2a4e8f # v0.20.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           markdownlint_flags: '**/*(*.md|*.md.j2)'