"Remove BLOCK_LIST" (#135729)

Summary:
Skip test_prepare_qat_conv_bn_fusion_getitem_placeholder when we use training ir, since it's only for bn-getitem pattern, but the pattern doesn't exist in training ir.

Remove BLOCK_LIST since it's empty.
Now all internal unittests will use training ir.

Test Plan:
```
buck2 run 'fbcode//mode/dev-nosan'  caffe2/test/quantization:test_quantization -- -r test_prepare_qat_conv_bn_fusion_getitem_placeholder
buck2 run 'fbcode//mode/dev-nosan'  caffe2/test:quantization_pt2e_qat -- -r test_prepare_qat_conv_bn_fusion_getitem_placeholder
```

Differential Revision: D62387987

Pull Request resolved: https://github.com/pytorch/pytorch/pull/135729
Approved by: https://github.com/tugsbayasgalan

test/quantization/pt2e/test_quantize_pt2e_qat.py

@@ -604,6 +604,9 @@ class TestQuantizePT2EQAT_ConvBn_Base(PT2EQATTestCase):
         is returned as part of the match anyway (as a placeholder).
         """
 
+        if capture_pre_autograd_graph_using_training_ir():
+            self.skipTest("Not applicable to training IR")
+
         class M(torch.nn.Module):
             def __init__(self, conv_class, bn_class):
                 super().__init__()

torch/_export/__init__.py

@@ -67,7 +67,7 @@ def capture_pre_autograd_graph_warning():
     log.warning("capture_pre_autograd_graph() is deprecated and doesn't provide any function guarantee moving forward.")
     log.warning("Please switch to use torch.export.export_for_training instead.")
     if config.is_fbcode():
-        log.warning("Unless the unittest is in the blocklist, capture_pre_autograd_graph() will fallback to torch.export.export_for_training.")  # noqa: B950
+        log.warning("For unittest, capture_pre_autograd_graph() will fallback to torch.export.export_for_training.")  # noqa: B950
 
 
 @compatibility(is_backward_compatible=False)