Parsing mujoco models with non-trivial mesh calculations is slow (especially in debug mode)

[RussTedrake]

What happened?

In #22370 and then #22401, have decided to disable a number of tests in details_mujoco_parser_examples_test with kTooSlow simply because the runtimes (especially in debug mode) are extremely poor.

I know that these models are making calls to CalcSpatialInertiaImpl(TriangleSurfaceMesh); Jeremy's Ctrl-C debugging pointed to MeshDistanceBoundary(TriangleSurfaceMesh): #22370 (comment)
More investigation (and a more specific issue description) is probably needed.

The victory condition is to remove the kTooSlow opt-out from that test.

Version

No response

What operating system are you using?

No response

What installation option are you using?

No response

Relevant log output

No response

[DamrongGuoy]

I can help with slow debug-mode MeshDistanceBoundary(TriangleSurfaceMesh). It might be related to #22311 that happened in CI too.