[WideEP] Remove pplx all2all backend (#33724)

Signed-off-by: Tyler Michael Smith <tlrmchlsmth@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

tests/kernels/moe/modular_kernel_tools/mk_objects.py

@@ -39,7 +39,6 @@ from vllm.utils.import_utils import (
     has_deep_ep,
     has_deep_gemm,
     has_mori,
-    has_pplx,
 )
 
 
@@ -238,19 +237,6 @@ if has_mori():
         supports_apply_weight_on_input=False,
     )
 
-if has_pplx():
-    from vllm.model_executor.layers.fused_moe.pplx_prepare_finalize import (
-        PplxPrepareAndFinalize,
-    )
-
-    register_prepare_and_finalize(
-        PplxPrepareAndFinalize,
-        batched_format,
-        common_float_and_int_types,
-        blocked_quantization_support=True,
-        backend="pplx",
-    )
-
 if has_flashinfer_cutlass_fused_moe() and current_platform.has_device_capability(100):
     from vllm.model_executor.layers.fused_moe.flashinfer_a2a_prepare_finalize import (  # noqa: E501
         FlashInferCutlassMoEPrepareAndFinalize,