Bump actions/checkout from 4 to 6 (#24)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/check.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-24.04
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy, rustfmt

.github/workflows/create-todo-issues.yml

@@ -19,7 +19,7 @@ jobs:
       issues: write
       contents: read
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: alstr/todo-to-issue-action@master
         env:
           MANUAL_COMMIT_REF: ${{ inputs.COMMIT_REF }}

.github/workflows/github-release.yml

@@ -12,7 +12,7 @@ jobs:
   create-release:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: taiki-e/create-gh-release-action@v1
         with:
           changelog: CHANGELOG.md