Arm backend: Fix decomposition logic for FP

[Erik-Lundell]

If the tosa_spec supports floating point, incorrect quantization is not a problem, and we can always
not decompose the ops_to_not_decompose.

cc @freddan80 @per @zingo @oscarandersson8218 @digantdesai

[pytorch-bot]

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❌ 1 New Failure, 1 Cancelled Job, 6 Unrelated Failures

As of commit a918f62 with merge base 747fc6f ():

NEW FAILURE - The following job has failed:

• trunk / test-qnn-model (fp32, vit) / linux-job (gh)
  RuntimeError: Command docker exec -t bdebe557478fccfd955419f49a7880ae95af1c72afa31c8002be87c0bdaa2b63 /exec failed with exit code 1

CANCELLED JOB - The following job was cancelled. Please retry:

• trunk / test-models-macos-coreml (emformer_join) / macos-job (gh)

FLAKY - The following job failed but was likely due to flakiness present on trunk:

• trunk / unittest-release / macos / macos-job (gh) (detected as infra flaky with no log or failing log classifier)

BROKEN TRUNK - The following jobs failed but was present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / linux / linux-job (gh) (trunk failure)
  backends/xnnpack/test/recipes/test_xnnpack_recipes.py::TestXnnpackRecipes::test_int8_static_quant_recipe
• pull / unittest / macos / macos-job (gh) (trunk failure)
  backends/xnnpack/test/recipes/test_xnnpack_recipes.py::TestXnnpackRecipes::test_int8_static_quant_recipe
• pull / unittest-editable / linux / linux-job (gh) (trunk failure)
  backends/xnnpack/test/recipes/test_xnnpack_recipes.py::TestXnnpackRecipes::test_int8_static_quant_recipe
• pull / unittest-editable / macos / macos-job (gh) (trunk failure)
  backends/xnnpack/test/recipes/test_xnnpack_recipes.py::TestXnnpackRecipes::test_int8_static_quant_recipe
• trunk / unittest-release / linux / linux-job (gh) (trunk failure)
  backends/xnnpack/test/recipes/test_xnnpack_recipes.py::TestXnnpackRecipes::test_int8_static_quant_recipe

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[Erik-Lundell]

Unrelated failure, should be buck safe.