Update dependency protobuf to v6

Author: renovate[bot]

llm_uncertainty_bench/requirements.txt

@@ -21,7 +21,7 @@ numpy==1.26.4
 packaging==25.0
 pandas==2.3.1
 Pillow==10.4.0
-protobuf==4.25.8
+protobuf==6.33.1
 psutil==5.9.8
 pyarrow==20.0.0
 pyarrow-hotfix==0.7