Bump actions/checkout from 1 to 3

Bumps [actions/checkout](https://github.com/actions/checkout) from 1 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v1...v3)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
       matrix:
         os: [ubuntu-20.04, ubuntu-22.04]
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v3
       - uses: ./
         with:
           ddevDir: tests/fixtures/ddevProj1