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_raysampling.py

@@ -639,4 +639,4 @@ class TestRaysampling(TestCaseMixin, unittest.TestCase):
                                 origin1, origin2, rtol=1e-4, atol=1e-4
                             ) == (id1 == id2), (origin1, origin2, id1, id2)
                             assert not torch.allclose(dir1, dir2), (dir1, dir2)
-                            self.assertClose(len1, len2), (len1, len2)
+                            self.assertClose(len1, len2)