fix: ignore temp files in scriptor watch mode (#223)

Anchor the .py regex to end-of-string so editor temp files like
  `foo.py.tmp.XXX` are no longer matched. Add an existence
  check before getmtime() as a second guard against race conditions
  where a transient file disappears before it can be processed.

Author: ArneGudermann

src/viur_cli/scriptor/cli.py

@@ -372,9 +372,10 @@ def watch_loop():
 
             def on_modified(event):
                 try:
-                    # check for tmp file
                     if event.src_path.endswith("~"):
                         return
+                    if not os.path.exists(event.src_path):
+                        return
                     if event.src_path not in modified_files:
                         modified_files[event.src_path] = os.path.getmtime(event.src_path)
                     elif os.path.getmtime(event.src_path) == modified_files[event.src_path]:
@@ -386,7 +387,7 @@ def on_modified(event):
                     print(f"Error: on file {event.src_path} {e}")
                     traceback.print_exc()
 
-            regexes = [r".*\.py"]
+            regexes = [r".*\.py$"]
             ignore_regexes = []
             ignore_directories = True
             case_sensitive = False