python: remove support for Boost::python

[davvid]

We no longer support USD < 25.11. Remove dead code.

Resolves: PUP-3206

[davvid]

Ah, it's interesting that the tests have issues on 25.11 only. If we'd like to handle that separately I could adjust the CI configs to omit 25.11 for now until we have a chance to investigate that. Let me know if you're okay with that approach.

[buddly27]

Ah, it's interesting that the tests have issues on 25.11 only. If we'd like to handle that separately I could adjust the CI configs to omit 25.11 for now until we have a chance to investigate that. Let me know if you're okay with that approach.

I think the failing test might be linked to this commit PixarAnimationStudios/OpenUSD@845f08c in v25.08.

From the CHANGELOG:

UsdStage will now dispatch finer grained change notifications for sublayer operations such as sublayer insertion/removal and layer muting/unmuting. This feature can be toggled via the PCP_ENABLE_MINIMAL_CHANGES_FOR_LAYER_OPERATIONS env var (default is on).

It could be worth toggling that env var to confirm whether it resolves the issue, but we’ll likely need to update the tests to align with the new behavior.

[davvid]

PCP_ENABLE_MINIMAL_CHANGES_FOR_LAYER_OPERATIONS

It could be worth toggling that env var to confirm whether it resolves the issue, but we’ll likely need to update the tests to align with the new behavior.

Sounds good. I'll take a stab at setting this variable to 0 tomorrow as a first step.

[davvid]

I've added a new commit that enables all of the newer USD versions alongside a change that sets the environment variable to 0 for now. Let's see if these pass now.

The version matrix is larger now, but we can trim it down in a subsequent change once we remove the variable and adapt the tests to the new expected behavior.

[buddly27]

Thanks! The tests are passing now.

The version matrix is larger now, but we can trim it down in a subsequent change once we remove the variable and adapt the tests to the new expected behavior.

Actually, since we are deprecating USD support under 25.11, we could drop v25.05 and v25.08 from the list

[davvid]

Actually, since we are deprecating USD support under 25.11, we could drop v25.05 and v25.08 from the list

Done. The latest commit now includes just 25.11 and 26.03.

[buddly27]

That's great, thanks David!