setuptools-scm warning raised when tag-pattern is not defined

[edgarrmondragon]

This package defaults to an empty string when tag-pattern is not defined by the user:

hatch-vcs/hatch_vcs/version_source.py

Lines 17 to 26 in e186a8b

	@property
	def config_tag_pattern(self):
	if self.__config_tag_pattern is None:
	tag_pattern = self.config.get('tag-pattern', '')
	if not isinstance(tag_pattern, str):
	raise TypeError('option `tag-pattern` must be a string')
	self.__config_tag_pattern = tag_pattern
	return self.__config_tag_pattern

This is causing setuptools-scm to raise a deprecation warning:

DeprecationWarning: Error getting the version from source `vcs`: empty regex for tag regex is invalid, using default

This warning is coming from https://github.com/pypa/setuptools_scm/blob/102f56a896bc4ea8d4c58d9c49f455f15310de38/src/setuptools_scm/_get_version_impl.py#L167-L175.

I don't know what the best solution is (if one's really needed) other than repeating setuptools_scm's default string value in this codebase.

[ofek]

Could we import the default value? I'm definitely open to PRs!