infra: bumpver: Use templating for the script

Let's make the script working between branching by getting the version
validation from the templates.

scripts/makebumpver

@@ -1,4 +1,11 @@
 #!/usr/bin/python3
+# ======================================
+# WARNING!
+# THIS FILE IS GENERATED FROM A TEMPLATE
+# DO NOT EDIT THIS FILE MANUALLY!
+# ======================================
+# The template is located in: makebumpver.j2
+
 #
 # makebumpver - Increment version number and add in RPM spec file changelog
 #               block.  Ensures rhel*-branch commits reference RHEL bugs.
@@ -121,8 +128,7 @@ class JIRAValidator:
     def validate_RHEL_issue_fixversion(self, bug):
         issue = self._query_RHEL_issue(bug)
 
-        # TODO: Switch this to template solution "distro_release"
-        valid_fix_version = "rhel-9"
+        valid_fix_version = rhel-9
         fix_version = issue.fields.fixVersions
         for version in fix_version:
             # Let's simplify and check only major version (ignore minor RHEL releases)