chore: Update outdated GitHub Actions versions

Author: pgoslatara

.github/workflows/docs.yml

@@ -29,7 +29,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0 # Fetch all history for git info
 

.github/workflows/lint.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Run markdownlint-cli2
         uses: DavidAnson/markdownlint-cli2-action@v19

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
       pull-requests: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           token: ${{ secrets.GITHUB_TOKEN }}