Fix dictionary merging in SCMInfo

Replaced the bitwise OR operator with the update method for merging dictionaries for 3.8 support

Author: coordt

bumpversion/scm.py

@@ -273,8 +273,8 @@ def latest_tag_info(cls, tag_name: str, parse_pattern: str) -> SCMInfo:
 
         commit_info = cls._commit_info(parse_pattern, tag_name)
         rev_info = cls._revision_info()
-        info |= commit_info
-        info |= rev_info
+        info.update(commit_info)
+        info.update(rev_info)
 
         return SCMInfo(**info)