Update actions/checkout action to v6 (#212)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/release.yml

@@ -8,7 +8,7 @@ jobs:
   dist:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: "0"
       - name: Build changelog from PRs with labels

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
   docs:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Check Docs
       run: make check
     - name: No diff