fix(crc_patch): Silence a deprecation warning

The crc_patch utility displays the following warning:

    bootloader/./crc_patch.py:31: DeprecationWarning: PY_SSIZE_T_CLEAN
        will be required for '#' formats

We cannot fix the offending library so disable the warnings to prevent
unnecessary build-log clutter.

Signed-off-by: Rahix <rahix@rahix.de>

bootloader/crc_patch.py

 #!/usr/bin/env python3
 import sys
+import warnings
+
+warnings.simplefilter("ignore")
 
 try:
     import crc16