chore(deps): update actions/checkout action to v4 (#27)

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

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
       image: erlang:${{ matrix.otp_version }}
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
       - name: Compile
         run: rebar3 compile
       - name: Run tests