[Backend Tester] Reduce log verbosity / spam (#13312)

When running tests, deprecation warnings for export_for_training and
"internal consistency verification was requested but not available"
create a large amount of spam in the CLI and drown out actual test info
during the run. Neither warning is particularly useful. I've suppressed
the the export_for_training warning in the backend tester only and
switched the tester to not request internal consistency verification
since it's not compiled into pybindings by default. This gives much
cleaner CLI output.

Before:
```
test_add_dtype_float32_xnnpack_static_int8_per_channel (test_add.Add.test_add_dtype_float32_xnnpack_static_int8_per_channel) ... /home/gregory/src/executorch/src/executorch/backends/test/harness/stages/quantize.py:50: FutureWarning: `torch.export.export_for_training` is deprecated and will be removed in PyTorch 2.10. Please use `torch.export.export` instead, which is functionally equivalent.
  captured_graph = export_for_training(artifact, inputs, strict=True).module()
/home/gregory/miniconda3/envs/executorch/lib/python3.12/site-packages/torchao/quantization/pt2e/utils.py:818: FutureWarning: `torch.export.export_for_training` is deprecated and will be removed in PyTorch 2.10. Please use `torch.export.export` instead, which is functionally equivalent.
  aten_pattern = torch.export.export_for_training(
/home/gregory/miniconda3/envs/executorch/lib/python3.12/site-packages/torchao/quantization/pt2e/utils.py:818: FutureWarning: `torch.export.export_for_training` is deprecated and will be removed in PyTorch 2.10. Please use `torch.export.export` instead, which is functionally equivalent.
  aten_pattern = torch.export.export_for_training(
/home/gregory/miniconda3/envs/executorch/lib/python3.12/site-packages/torchao/quantization/pt2e/utils.py:818: FutureWarning: `torch.export.export_for_training` is deprecated and will be removed in PyTorch 2.10. Please use `torch.export.export` instead, which is functionally equivalent.
  aten_pattern = torch.export.export_for_training(
/home/gregory/miniconda3/envs/executorch/lib/python3.12/site-packages/torchao/quantization/pt2e/utils.py:818: FutureWarning: `torch.export.export_for_training` is deprecated and will be removed in PyTorch 2.10. Please use `torch.export.export` instead, which is functionally equivalent.
... (it logs like 20x per test)
```

After:
```
test_add_dtype_float32_xnnpack (test_add.Add.test_add_dtype_float32_xnnpack) ... ok
test_add_dtype_float32_xnnpack_static_int8_per_channel (test_add.Add.test_add_dtype_float32_xnnpack_static_int8_per_channel) ... ok
test_add_f32_alpha_xnnpack (test_add.Add.test_add_f32_alpha_xnnpack) ... ok
test_add_f32_alpha_xnnpack_static_int8_per_channel (test_add.Add.test_add_f32_alpha_xnnpack_static_int8_per_channel) ... ERROR
...
```

Author: GregoryComer

backends/test/harness/stages/serialize.py

@@ -13,6 +13,7 @@
 try:
     from executorch.extension.pybindings.portable_lib import (  # @manual
         _load_for_executorch_from_buffer,
+        Verification,
     )
 except ImportError as e:
     logger.warning(f"{e=}")
@@ -39,7 +40,9 @@ def graph_module(self) -> None:
 
     def run_artifact(self, inputs):
         inputs_flattened, _ = tree_flatten(inputs)
-        executorch_module = _load_for_executorch_from_buffer(self.buffer)
+        executorch_module = _load_for_executorch_from_buffer(
+            self.buffer, program_verification=Verification.Minimal
+        )
         executorch_output = copy.deepcopy(
             executorch_module.run_method("forward", tuple(inputs_flattened))
         )

backends/test/suite/runner.py

@@ -3,6 +3,7 @@
 import re
 import time
 import unittest
+import warnings
 
 from datetime import timedelta
 from typing import Any
@@ -249,6 +250,10 @@ def build_test_filter(args: argparse.Namespace) -> TestFilter:
 def runner_main():
     args = parse_args()
 
+    # Suppress deprecation warnings for export_for_training, as it generates a
+    # lot of log spam. We don't really need the warning here.
+    warnings.simplefilter("ignore", category=FutureWarning)
+
     begin_test_session(args.report)
 
     if len(args.suite) > 1: