Pin protobuf (#14512)

Author: carmocca

requirements/pytorch/extra.txt

@@ -9,3 +9,4 @@ hydra-core>=1.0.5, <1.3.0
 jsonargparse[signatures]>=4.12.0, <=4.12.0
 gcsfs>=2021.5.0, <2022.8.0
 rich>=10.14.0, !=10.15.0.a, <13.0.0
+protobuf<=3.20.1 # strict  # an extra is updating protobuf, this pin prevents TensorBoard failure