ci(fuzzing): treat timeout as a successful workflow run

If we hit the fuzzing timeout, it means no crashes happenened,
therefore it makes no sense to treat it as a workflow failure.

"timeout" returns an exit code 124 when this happens,
and by default the Github runners treat non-zero ones as a failure.

Change the logic to convert the exit code 124 to 0 (success)
and pass everything else (legitimate failures) through.

Closes #5244.

Signed-off-by: Alex T. <[email protected]>

Author: alex-ter

.github/workflows/fuzzing.yml

@@ -103,4 +103,10 @@ jobs:
           at_index=$(((10#$(date -u +%U)) % ${#fuzzing_scripts[@]}))
           selected_script="${fuzzing_scripts[$at_index]}"
           echo "Selected script: $selected_script"
-          timeout --preserve-status --signal=SIGINT 60m python $selected_script
+          # Disable the default Github runner fail-fast behaviour for better timeout handling
+          set +e
+          timeout --signal=SIGINT 60m python $selected_script
+          # "timeout" returns 124 when the command times out.
+          # We treat this as a success (nothing found during the allotted time) and pass other exit codes through.
+          fuzz_exitcode=$?
+          [ $fuzz_exitcode -eq 124 ] && exit 0 || exit $fuzz_exitcode