Prevent error log if no file was created

In case no report is created, there is an error message which is not useful :
`ls: cannot access 'build/sanitizer_report*': No such file or directory`
This case is treated in the else condition already.

.github/workflows/code_sanitizers.yml

@@ -66,7 +66,7 @@ jobs:
         run: |
           (
             issue_reported=false
-            reports=$(ls build/sanitizer_report*)
+            reports=$(ls build/sanitizer_report* 2>/dev/null)
             if [[ -n "${reports}" ]]; then
               echo "Report Output:"
               for report in ${reports}; do