Bump actions/checkout from 3 to 4 (#49)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to
4.

.github/workflows/dependency-graph.yml

@@ -8,6 +8,6 @@ jobs:
     name: Update Dependency Graph
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: sbt/setup-sbt@v1
       - uses: scalacenter/sbt-dependency-submission@v3