ci: pipeline_message: ignore generated errors

Currently marge does not ignore the word `generated` when she is searching
the logs for a relevant error message. So, marge's comments on a failed
pipeline say something unhelpful like "errors generated"

Example:
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32687#note_2706792
https://gitlab.freedesktop.org/mesa/mesa/-/pipelines/1332129

Ignore the word `generated` so marge will provide more useful comments.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32773>

.marge/hooks/pipeline_message.py

@@ -221,6 +221,8 @@ async def search_job_log_for_errors(session, project_id, job):
         "building c",
         "error_msg      : None",
         "error_type",
+        "error generated",
+        "errors generated",
         "exit code",
         "exit status",
         "exiting now",

bin/ci/test/test_pipeline_message.py

@@ -172,6 +172,8 @@ async def test_search_job_log_for_errors(mock_get_job_log):
 
     job_log = r"""
 error_msg: something useful
+1 error generated
+3 errors generated.
 -- Looking for strerror_r - found
 -- Looking for strerror_s - not found
 [49/176] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ErrorHandling.cpp.o