Enable all Windows tests / remove pytest-windows.ini

Summary

This is the tracking issue for enablement of the remaining unit tests on Windows and subsequent removal of pytest-windows.ini. This file is a copy of pytest.ini with additional tests disabled (see https://github.com/pytorch/executorch/pull/13716). It is intended that the main pytest.ini is eventually used once all tests are enabled.

I've taken a quick look through the remaining (disabled) failing tests and haven't seen anything obviously critical, though there are a lot of tests gated behind tokenizers. The remaining failing tests mostly failed due to file IO failures and likely need updates to paths on Windows or similar. We should nonetheless prioritize enabling these tests to ensure that we don't miss anything.

Remaining Work

• Enable Windows support for tokenizers, enable extension/llm and LLM example tests.
  • Merge https://github.com/meta-pytorch/tokenizers/pull/121.
• Enable extension/pybindings/test/test_pybindings.py::PybindingsTest::test_method_quantized_ops
• Enable extension/pybindings/test/test_pybindings.py::PybindingsTest::test_quantized_ops
• Enable runtime/test/test_runtime.py::RuntimeTest::test_load_program_with_path
• Enable exir/backend/test/test_compatibility.py::TestCompatibility::test_compatibility_in_runtime
• Enable exir/backend/test/test_compatibility.py::TestCompatibility::test_compatibility_in_runtime_edge_program_manager
• Enable exir/backend/test/test_lowered_backend_module.py::TestBackendAPI::test_emit_lowered_backend_module_end_to_end
• Enable exir/backend/test/test_to_backend_multi_method.py::TestToBackendMultiMethod::test_multi_method_end_to_end
• Enable extension/llm/custom_ops/test_sdpa_with_kv_cache.py::SDPATestForSpeculativeDecode::test_sdpa_with_cache_seq_len_130
• Enable devtools/inspector/tests/inspector_test.py::TestInspector::test_etrecord_populates_correct_edge_dialect_aot_intermediate_outputs
• Enable devtools/inspector/tests/inspector_test.py::TestInspector::test_etrecord_populates_correct_export_program_aot_intermediate_outputs
• Enable runtime/test/test_runtime_etdump_gen.py::RuntimeETDumpGenTest::test_etdump_generation
• Enable method_test (native).
• Enable tensor_parser_test (native).