Allow third-party versions to end in asterisk (#6129)

This is a first step towards #6095, where x.y and x.y.* are treated as
equivalent. The next step is to update existing versions to use x.y.*
where applicable and then treat x.y differently.

Co-authored-by: Akuli <akuviljanen17@gmail.com>

tests/check_consistent.py

@@ -169,7 +169,7 @@ def check_metadata():
         assert "version" in data, f"Missing version for {distribution}"
         version = data["version"]
         msg = f"Unsupported Python version {version}"
-        assert re.match(r"^\d+\.\d+(\.\d+)?$", version), msg
+        assert re.match(r"^\d+(\.\d+)*(\.\*)?$", version), msg
         for key in data:
             assert key in metadata_keys, f"Unexpected key {key} for {distribution}"
         assert isinstance(data.get("python2", False), bool), f"Invalid python2 value for {distribution}"