Re-enable file fixes and suppress lcov warnings

disable_file_fixes broke path resolution — Codecov needs it to map
absolute CI paths to repo-relative paths. Also suppress geninfo
mismatch/negative/gcov warnings (doubled --ignore-errors syntax).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: facontidavide

.github/workflows/cmake_ubuntu.yml

@@ -83,8 +83,9 @@ jobs:
       run: |
         lcov --capture --directory build/Debug \
              --output-file coverage.info \
-             --ignore-errors mismatch \
-             --ignore-errors negative
+             --ignore-errors mismatch,mismatch \
+             --ignore-errors negative,negative \
+             --ignore-errors gcov,gcov
         lcov --extract coverage.info \
              '*/BehaviorTree.CPP/include/*' \
              '*/BehaviorTree.CPP/src/*' \
@@ -102,7 +103,7 @@ jobs:
         files: coverage.info
         flags: unittests
         disable_search: true
-        disable_file_fixes: true
+        disable_file_fixes: false
         plugins: noop
         network_filter: >-
           include/behaviortree_cpp/,src/