USHIFT-2966: ensure the output of git push is in the traceback if the…

…re is an error

scripts/release-notes/gen_ec_release_notes.py

@@ -418,12 +418,15 @@ def tag_release(tag, sha, buildtime):
         check=True,
     )
     print(f'git push origin {tag}')
-    subprocess.run(
+    completed = subprocess.run(
         ['git', 'push', 'origin', tag],
         env=env,
-        check=True,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
     )
-
+    output = completed.stdout.decode('utf-8') if completed.stdout else ''
+    if completed.returncode != 0:
+        raise subprocess.CalledProcessError(completed.returncode, cmd, output)
 
 def publish_release(new_release, take_action):
     """Does the work to tag and publish a release.