ci(pre-commit): Remove version_files lookahead

Commitizen runs bump on itself to, among other things, manage the
version it uses of its own pre-commit hooks. When searching
.pre-commit-config.yaml for the version number of Commitizen, we search
for "Commitizen," which is in a comment to the right of the version
number. Remove the lookahead assertion for "Commitizen," and instead
simply consume it when matching now that version_files regexes don't
need to exclusively match to the left of the version number.

pyproject.toml

@@ -4,7 +4,7 @@ tag_format = "v$version"
 version_files = [
   "pyproject.toml:version",
   "commitizen/__version__.py",
-  ".pre-commit-config.yaml:rev:.\\s+(?=[^\\n]+Commitizen)"
+  ".pre-commit-config.yaml:rev:.+Commitizen"
 ]
 
 [tool.black]