fix: handle empty release asset delete responses

.gitea/workflows/ota-build.yml

@@ -93,7 +93,14 @@ jobs:
               payload = None if data is None else json.dumps(data).encode()
               r = Request(url, data=payload, headers=h, method=method)
               with urlopen(r, timeout=120) as resp:
-                  return json.loads(resp.read().decode()) if resp.readable() else None
+                  body = resp.read()
+              if not body:
+                  return None
+              text = body.decode()
+              try:
+                  return json.loads(text)
+              except json.JSONDecodeError:
+                  return text
 
           try:
               release = req(f"{api}/releases/tags/{tag}")