ci: fix lcov dir + upload build tree with .gcno/.gcda

Author: Simon

.github/workflows/ci.yml

@@ -80,7 +80,7 @@ jobs:
 
       - name: Collect code-coverage data
         run: |
-          lcov --directory . --capture --output-file coverage.info
+          lcov --directory build/Linux/x64/Debug --capture --output-file coverage.info
           lcov --remove coverage.info '/usr/*' '${{ github.workspace }}/cts/*' --output-file coverage.info
           lcov --list coverage.info
 
@@ -90,6 +90,7 @@ jobs:
           name: openvx-build
           path: |
             ${{ env.INSTALL_PREFIX }}/
+            build/Linux/x64/Debug/
             build-cts/
             cts/test_data/
             coverage.info