build: fix success message in verify_release

Prior to theupdateframework#1946 the verify_release script was successful if both PyPI
and GitHub release artifacts matched the local build.

Now, if the `--skip-pypi` option is provided, the script can also
be successful if only the GitHub release artifacts match the local
build.

This commit splits the final success message in two separate
success messages, one for PyPI and one for GitHub.

verify_release

@@ -172,15 +172,16 @@ def main() -> int:
                 # This is expected while build is not reproducible
                 finished("ERROR: PyPI artifacts do not match built release")
                 success = False
+            else:
+                finished(f"PyPI artifacts match the built release")
 
         progress("Downloading release from GitHub")
         if not verify_github_release(build_version, build_dir):
             # This is expected while build is not reproducible
             finished("ERROR: GitHub artifacts do not match built release")
             success = False
-
-        if success:
-            finished("Github and PyPI artifacts match the built release")
+        else:
+            finished(f"GitHub artifacts match the built release")
 
     return 0 if success else 1