Revert default grep context to 5

This commit changes the default value for the `--grep-context`
argument in the `print_workflow_run_errors.py` script back to 5
(from 10).

Author: google-labs-jules[bot]

scripts/print_workflow_run_errors.py

@@ -310,8 +310,8 @@ def parse_repo_url_arg(url_string):
   parser.add_argument(
       "--grep-context", "-C",
       type=int,
-      default=10,
-      help="Number of lines of leading and trailing context to print for grep matches. Default: 10."
+      default=5,
+      help="Number of lines of leading and trailing context to print for grep matches. Default: 5."
   )
   parser.add_argument(
       "--job-pattern",