build(deps): bump actions/checkout from 1 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 1 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v1...v4)

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

Note: The version is left at v1 in the `linux32` job because that one
runs in a Docker container that does not support Node.js, and hence the
Action needs to stay at a version that works without Node.js (i.e. v1).

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

.github/workflows/main.yml

@@ -316,7 +316,7 @@ jobs:
       CC: clang
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: ci/install-dependencies.sh
     - run: ci/run-build-and-minimal-fuzzers.sh
   dockerized: