GHA: Use CodeCov action for upload

Author: Flamefire

.github/workflows/unit-tests.yml

@@ -212,12 +212,23 @@ jobs:
       - name: Test
         run: tools/ci/test.sh
 
-      - run: tools/ci/collectCoverageData.sh && external/libutil/tools/ci/uploadCoverageData.sh
+      - run: tools/ci/collectCoverageData.sh
         if: matrix.coverage && success()
 
       - run: tools/ci/checkTestCoverage.sh
         if: matrix.coverage && success()
 
+      - name: Upload coverage (Codecov)
+        if: matrix.coverage && success()
+        uses: codecov/codecov-action@57e3a136b779b570ffcdbf80b3bdc90e7fab3de2 # v6.0.0
+        with:
+          fail_ci_if_error: true
+          disable_search: true
+          files: coverage.info
+          name: Github Actions
+          token: ${{secrets.CODECOV_TOKEN}}
+          verbose: true
+
       - name: Upload coverage (Coveralls)
         if: matrix.coverage && success()
         uses: coverallsapp/github-action@5cbfd81b66ca5d10c19b062c04de0199c215fb6e # v2.3.7