ci: Handle payload elements as not set/None

alt motive: Re-trigger GHAs that have been showing waiting for too
long ;)

.github/helper/documentation.py

@@ -32,9 +32,9 @@ if __name__ == "__main__":
 
 	if response.ok:
 		payload = response.json()
-		title = payload.get("title", "").lower()
-		head_sha = payload.get("head", {}).get("sha")
-		body = payload.get("body", "").lower()
+		title = (payload.get("title") or "").lower()
+		head_sha = (payload.get("head") or {}).get("sha")
+		body = (payload.get("body") or "").lower()
 
 		if title.startswith("feat") and head_sha and "no-docs" not in body:
 			if docs_link_exists(body):