Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/elixir.yml

@@ -33,7 +33,7 @@ jobs:
           - 5432:5432
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Elixir
         uses: erlef/setup-beam@c2e02f777c158310fc6d3d4e11b36a52d2d52db8
         with:
@@ -56,7 +56,7 @@ jobs:
     name: Format
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Elixir
         uses: erlef/setup-beam@c2e02f777c158310fc6d3d4e11b36a52d2d52db8
         with:
@@ -76,7 +76,7 @@ jobs:
     name: Dialyzer
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Elixir
         uses: erlef/setup-beam@c2e02f777c158310fc6d3d4e11b36a52d2d52db8
         with: