chore: upload coverage of unittests together (#2301)

* chore: upload coverage of unittests together

Before this each run for respective OS carried out upload to codecov
server however this consumes codecov tokenless upload limit.

Signed-off-by: Matej Vašek <mvasek@redhat.com>

* fixup: decrease artifact retention period

Signed-off-by: Matej Vašek <mvasek@redhat.com>

* fixup: added the checkout action

I would not expect that this would be needed for codecov upload.

Signed-off-by: Matej Vašek <mvasek@redhat.com>

---------

Signed-off-by: Matej Vašek <mvasek@redhat.com>

.github/workflows/test-unit.yaml

@@ -36,7 +36,24 @@ jobs:
           FUNC_REPO_BRANCH_REF: ${{ github.head_ref }}
       - name: Template Unit Tests
         run: make test-templates
+      - name: "Archive code coverage results"
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-${{ matrix.os }}
+          path: ./coverage.txt
+          retention-days: 1
+  upload-coverage:
+    needs: [test]
+    name: "Upload coverage"
+    runs-on: "ubuntu-latest"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Download Coverage
+        run: |
+          gh run download -R ${{ github.repository }} ${{ github.run_id }}
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - uses: codecov/codecov-action@v4
         with:
-          files: ./coverage.txt
-          flags: unit-tests-${{ matrix.os }}
+          files: ./coverage-ubuntu-latest/coverage.txt,./coverage-windows-latest/coverage.txt,./coverage-macos-latest/coverage.txt
+          flags: unit-tests