chore(deps): remove unused mmcv and mmengine dependencies

Both were leftovers from the dead Detic integration (import commented
out, directory excluded from mypy). Zero imports of either package
anywhere in the codebase. Removing them eliminates slow source builds
and 3 transitive packages from uv sync.

Author: spomichter

pyproject.toml

@@ -200,8 +200,6 @@ cuda = [
     "nvidia-nvimgcodec-cu12[all]; platform_machine == 'x86_64'",
     "onnxruntime-gpu>=1.17.1; platform_machine == 'x86_64'", # Only versions supporting both cuda11 and cuda12
     "ctransformers[cuda]==0.2.27",
-    "mmengine>=0.10.3",
-    "mmcv>=2.1.0",
     "xformers>=0.0.20; platform_machine == 'x86_64'",
 ]
 
@@ -308,7 +306,6 @@ base = [
 
 
 [tool.uv]
-no-build-isolation-package = ["mmcv"]
 constraint-dependencies = ["setuptools<82"]
 
 [tool.ruff]