Ignore Discord IDs for commit links

[trag1c]

We're currently doing a lot of requests any time a person/channel gets mentioned. Someone trying to use an ~18-char long string of digits to refer to a Ghostty commit is just not happening (and when it is they should use ghostty@ or main@).

[00-kat]

Alternatively we could just ignore mentions by repurposing this:

discord-bot/packages/toolbox/src/toolbox/message_moving/moved_message.py

Lines 9 to 22 in 8bd727d

	_SNOWFLAKE_REGEX = re.compile(r"<(\D{0,2})(\d+)>", re.ASCII)
	def _find_snowflake(content: str, type_: str) -> tuple[int, int] | tuple[None, None]:
	"""
	WARNING: this function does not account for Markdown features such as code blocks
	that may disarm a snowflake.
	"""
	# NOTE: while this function could just return tuple[int, int] | None, that makes it
	# less convenient to destructure the return value.
	snowflake = _SNOWFLAKE_REGEX.search(content)
	if snowflake is None or snowflake[1] != type_:
	return None, None
	return int(snowflake[2]), snowflake.span()[0]