Update default timer script to remove request parameter

- Modify default timer script to remove unused `req` parameter
- Simplify default script signature to match current usage

routes/timer.py

@@ -136,7 +136,7 @@ FOR EACH ROW
 EXECUTE PROCEDURE fn_increment_invocation_count();
 '''
 
-DEFAULT_SCRIPT = """async (req) => {
+DEFAULT_SCRIPT = """async () => {
     environment.count += 1
     console.log(`Executing ${environment.count}`)
 }"""