Remove unused boost dependency; OpenUSD vendors its own pxr_boost

[oursland]

OpenUSD 24.11+ replaced boost::python with a vendored, namespace-mangled pxr_boost and no longer links external boost in the default build. This recipe enables only PXR_ENABLE_PYTHON_SUPPORT (no OpenVDB/OpenImageIO), so nothing links libboost: all boost symbols resolve to the in-package libusd_boost, and the remaining <boost/...> includes in public headers are behind opt-in guards (PXR_BOOST_PYTHON_HAS_BOOST_SHARED_PTR, PEGTL's legacy-compiler fallback).

libboost-devel is kept in host for the build, but its run-export is ignored since the built libraries link only the vendored libusd_boost, never external libboost. (Note: this still leaves openusd subject to boost-migration rebuilds, which become no-ops.) Bump build number for the rebuild.

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• Reset the build number to 0 (if the version changed)
• Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• Ensured the license file is being packaged.

[oursland]

@traversaro I think this PR should be merged before the TBB 2023 one to increase compatibility.

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipe/recipe.yaml) and found some lint.

Here's what I've got...

For recipe/recipe.yaml:

• ❌ Recipe maintainer "oursland." does not exist

For recipe/recipe.yaml:

• ℹ️ azure.settings_win.variables.CONDA_BLD_PATH is deprecated, please use workflow_settings.build_workspace_dir instead.
• ℹ️ azure.settings_win.variables.MINIFORGE_HOME is deprecated, please use workflow_settings.tools_install_dir instead.
• ℹ️ 'Free Disk Space' is deprecated.
  Deprecated. Use workflow_settings.free_disk_space instead.
  Free up disk space before build.
  The following components can be cleaned up: apt, cache, docker.
  When set to true, only apt and cache are cleaned up.
  Set it to the full list to clean up all components.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/27931669399. Examine the logs at this URL for more detail.}

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/recipe.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe/recipe.yaml:

• ℹ️ azure.settings_win.variables.CONDA_BLD_PATH is deprecated, please use workflow_settings.build_workspace_dir instead.
• ℹ️ azure.settings_win.variables.MINIFORGE_HOME is deprecated, please use workflow_settings.tools_install_dir instead.
• ℹ️ 'Free Disk Space' is deprecated.
  Deprecated. Use workflow_settings.free_disk_space instead.
  Free up disk space before build.
  The following components can be cleaned up: apt, cache, docker.
  When set to true, only apt and cache are cleaned up.
  Set it to the full list to clean up all components.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/27934297156. Examine the logs at this URL for more detail.}

[traversaro]

Thanks! I am probably missing something, if boost is not used, can't we just remove the libboost-devel dependency instead of ignoring its run_exports ?

[oursland]

I wasn't 100% sure Boost wasn't used, but it's not exported and therefore doesn't require compatibility in depending projects. I've removed it altogether in the latest force push. Hopefully it will build and pass tests.

[traversaro]

It seems that indeed (non vendored/forked) boost is not used at all!