Fix regex for parsing version from GITHUB_REF

Author: impredicative

setup.py

@@ -20,7 +20,7 @@ def parse_requirements(filename: str) -> List[str]:
     name="bitlyshortener",
     author="Ouroboros Chrysopoeia",
     author_email="[email protected]",
-    version=cast(Match, re.fullmatch(r"refs/tags/v(?P<ver>\S+)", os.environ["GITHUB_REF"]))["ver"],  # Ex: GITHUB_REF="refs/tags/v1.2.3"; version="1.2.3"
+    version=cast(Match, re.fullmatch(r"refs/tags/v?(?P<ver>\S+)", os.environ["GITHUB_REF"]))["ver"],  # Ex: GITHUB_REF="refs/tags/1.2.3"; version="1.2.3"
     description="High-volume Bitly V4 URL shortener with memory-cache",
     keywords="bitly url shortener",
     long_description=(_DIR / "README.md").read_text().strip(),