Bump sersoft-gmbh/swift-coverage-action from 3 to 4

Bumps [sersoft-gmbh/swift-coverage-action](https://github.com/sersoft-gmbh/swift-coverage-action) from 3 to 4.
- [Release notes](https://github.com/sersoft-gmbh/swift-coverage-action/releases)
- [Commits](sersoft-gmbh/swift-coverage-action@v3...v4)

---
updated-dependencies:
- dependency-name: sersoft-gmbh/swift-coverage-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/swift-test.yml

@@ -57,7 +57,7 @@ jobs:
       - name: Build & Test
         run: swift test -v --parallel --enable-code-coverage
       - name: Generate Coverage Files
-        uses: sersoft-gmbh/swift-coverage-action@v3
+        uses: sersoft-gmbh/swift-coverage-action@v4
         id: coverage-files
       - uses: codecov/codecov-action@v3
         with:
@@ -136,7 +136,7 @@ jobs:
           parallel-testing-enabled: ${{ matrix.platform != 'watchOS' }}
           enable-code-coverage: true
           derived-data-path: .derived-data
-      - uses: sersoft-gmbh/swift-coverage-action@v3
+      - uses: sersoft-gmbh/swift-coverage-action@v4
         id: coverage-files
         with:
           search-paths: |