Pre-commit install fails if existing hook is not utf-8

[sbienkow-ninja]

It looks like pre-commit tries to read the contents of an already installed hook blindly, without first checking if its a text file and not binary blob.

version information

pre-commit version: 2.13.0
sys.version:
    3.8.5 (default, May 27 2021, 13:30:53) 
    [GCC 9.3.0]
sys.executable: /usr/bin/python3
os.name: posix
sys.platform: linux

error information

An unexpected error has occurred: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc8 in position 40: invalid continuation byte

Traceback (most recent call last):
  File "/home/user/.local/lib/python3.8/site-packages/pre_commit/error_handler.py", line 65, in error_handler
    yield
  File "/home/user/.local/lib/python3.8/site-packages/pre_commit/main.py", line 367, in main
    return install(
  File "/home/user/.local/lib/python3.8/site-packages/pre_commit/commands/install_uninstall.py", line 139, in install
    _install_hook_script(
  File "/home/user/.local/lib/python3.8/site-packages/pre_commit/commands/install_uninstall.py", line 88, in _install_hook_script
    if os.path.lexists(hook_path) and not is_our_script(hook_path):
  File "/home/user/.local/lib/python3.8/site-packages/pre_commit/commands/install_uninstall.py", line 52, in is_our_script
    contents = f.read()
  File "/usr/lib/python3.8/codecs.py", line 322, in decode
    (result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc8 in position 40: invalid continuation byte