fix: use compact JSON in ANC hotfix injection (#8410)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Devinwong

hotfix/anc_hotfix_generate.py

@@ -50,7 +50,7 @@ def read_hotfix_version():
 
 def build_hotfix_entry(version):
     """Build the write_files YAML lines for the hotfix JSON config."""
-    hotfix_json = json.dumps({"version": version})
+    hotfix_json = json.dumps({"version": version}, separators=(',', ':'))
     return [
         f"\n",
         f"{BEGIN_MARKER}\n",