chore: update GH checkout action (#50)

Author: marvinhagemeister

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
   lint-and-format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: denoland/setup-deno@v1
       - run: deno fmt --check
       # TODO