Tools: Update Writeme check (#7507)

* Update readme return logic.

* Update runner.py

Just touching this file for GH action testing.

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Co-authored-by: Jason Q <81179619+beqqrry-aws@users.noreply.github.com>

Author: rlhagerm

.tools/readmes/runner.py

@@ -190,7 +190,10 @@ def writeme(
         print(failed_list)
         print("Rerun writeme.py to update README links and sections.")
     print("WRITEME Run completed.")
-    return len(failed)
+    fail_count = len(failed)
+    if fail_count > 0:
+        raise typer.Exit(code=fail_count) # Return a non-zero code through typer so Github check will fail. 
+    return fail_count
 
 
 def make_diff(renderer, id):