Bump codecov/codecov-action from 1 to 4

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

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/main.linux.temurin.lts.yml

@@ -36,6 +36,6 @@ jobs:
           name: test-images
           path: ./com.io7m.digal.tests/testCSS.png
       - name: Coverage
-        uses: codecov/codecov-action@v1
+        uses: codecov/codecov-action@v4
         with:
           file: com.io7m.digal.tests/target/site/jacoco-aggregate/jacoco.xml