bpo-44313: bump up magic (#26983)

Author: isidentical

Lib/importlib/_bootstrap_external.py

@@ -370,7 +370,7 @@ def _write_atomic(path, data, mode=0o666):
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3457).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3458).to_bytes(2, 'little') + b'\r\n'
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little')  # For import.c
 
 _PYCACHE = '__pycache__'