chore(deps): update actions/checkout action to v6 (#2)

| datasource  | package          | from | to |
| ----------- | ---------------- | ---- | -- |
| github-tags | actions/checkout | v4   | v6 |

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

Author: renovate[bot]

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
     if: "!startsWith(github.event.head_commit.message, 'chore(release):')"
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@stable
@@ -109,7 +109,7 @@ jobs:
           private-key: ${{ secrets.BOT_APP_PRIVATE_KEY }}
 
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           ref: v${{ needs.release.outputs.new_release_version }}
           token: ${{ steps.generate_token.outputs.token }}