test fixes and lints

Summary:
- followup recent pyre change D63415925
- make tests remove temporary files
- weights_only=True in torch.load
- lint fixes

3 test fixes from VRehnberg in https://github.com/facebookresearch/pytorch3d/issues/1914
- imageio channels fix
- frozen decorator in test_config
- load_blobs positional

Reviewed By: MichaelRamamonjisoa

Differential Revision: D66162167

fbshipit-source-id: 7737e174691b62f1708443a4fae07343cec5bfeb

tests/test_build.py

@@ -43,7 +43,7 @@ class TestBuild(unittest.TestCase):
         tutorials = sorted(tutorials_dir.glob("*.ipynb"))
 
         for tutorial in tutorials:
-            with open(tutorial) as f:
+            with open(tutorial, encoding="utf8") as f:
                 json.load(f)
 
     @unittest.skipIf(in_conda_build or in_re_worker, "In conda build, or RE worker")