ci: don't fail pipeline on Codecov upload error

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: MSACC

.github/workflows/tests.yml

@@ -87,5 +87,5 @@ jobs:
         with:
           flags: unit
           verbose: true
-          fail_ci_if_error: true
+          fail_ci_if_error: false