[Deps] Bump USD Core to 26.5

[AntoineRichard]

Description

Raises the kit-less usd-core dependency from >=25.11,<26.0 to
>=26.5,<27.0 so Isaac Lab picks up the upstream fix for crashes while
parsing colliders concurrently.

Newton's pinned importer metadata still declares usd-core<26.5, so this PR
adds a narrow uv override for x86_64/AMD64 until that metadata catches up. The
lock resolves usd-core 26.8 for the supported Linux x86_64 and Windows
platforms. This intentionally excludes the unrelated Newton runtime changes
from #6301.

Type of change

• Breaking change (extensions built against USD 25 must be rebuilt against
  USD 26)

Screenshots

Not applicable.

Verification

• ./isaaclab.sh -p -m pytest source/isaaclab/test/cli/test_source_package_metadata.py
  (2 passed)
• ./isaaclab.sh -p tools/changelog/cli.py check develop
• ./isaaclab.sh -f
• Fresh uv resolution (472 packages, usd-core 26.8)

No new test was added; the existing hard-coded USD dependency guard was
updated for the new ABI range.

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made the corresponding changelog update
• My changes generate no new warnings
• I have added a changelog fragment for every touched package
• My name already exists in CONTRIBUTORS.md

[greptile-apps]

Greptile Summary

The PR upgrades kit-less OpenUSD from the USD 25 ABI to USD 26 and overrides Newton's stale resolver constraint.

• Raises the x86_64/AMD64 usd-core range to >=26.5,<27.0.
• Resolves usd-core 26.8 for Linux x86_64 and Windows.
• Updates the dependency guard and adds a breaking-change changelog fragment.
• Leaves the now-obsolete single-threaded OpenUSD rendering workaround enabled.

Confidence Score: 4/5

The PR appears safe to merge, with a non-blocking cleanup needed to re-enable OpenUSD worker concurrency in kit-less rendering.

The dependency and lock changes consistently select USD 26 for the stated supported platforms, but the rendering harness still forces PXR_WORK_THREAD_LIMIT=1 even though the upgraded minimum fixes the race that required it.

Files Needing Attention: pyproject.toml and source/isaaclab/test/rendering/rendering_test_utils.py

Important Files Changed

Filename	Overview
pyproject.toml	Raises the kit-less USD dependency and adds the Newton override, but does not retire the concurrency workaround whose removal condition is now satisfied.
uv.lock	Records the new override and resolves usd-core 26.8 wheels for supported Linux x86_64 and Windows targets.
source/isaaclab/test/cli/test_source_package_metadata.py	Updates the metadata assertion to enforce the new USD 26 dependency range.
source/isaaclab/changelog.d/antoiner-usd-core-26-5.major.rst	Clearly documents the ABI-breaking dependency upgrade and required extension rebuild.

_{Reviews (1): Last reviewed commit: "Bump USD Core to 26.5" | Re-trigger Greptile}

[greptile-apps]

Obsolete concurrency workaround remains

Raising the minimum to usd-core>=26.5 satisfies the documented condition for removing PXR_WORK_THREAD_LIMIT=1, but the rendering harness still disables OpenUSD worker concurrency, increasing kit-less workflow runtime and leaving the upgraded concurrent path untested.

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!

[isaaclab-review-bot]

Isaac Lab Review Bot

The USD 26 dependency update and lockfile are internally consistent for project-level uv sync, but the published wheel metadata retains an unresolved conflict between usd-core>=26.5 and Newton importers requiring usd-core<26.5.

• Design and architecture: The Newton compatibility workaround is implemented only through [tool.uv].override-dependencies. Because that override is not part of distributed wheel metadata, it does not protect the documented wheel installation path.
• API: The breaking USD ABI range is clearly declared and documented in the major changelog fragment with rebuild guidance. However, the resulting published dependency contract is unsatisfiable on x86_64/AMD64 while the selected Newton importer metadata retains its <26.5 bound.
• Implementation: The lockfile correctly resolves usd-core 26.8 for the configured Linux x86_64 and Windows environments, and the metadata guard reflects the new range. Before merge, the wheel-install producer/consumer path needs a distributed Newton requirement compatible with USD 26.5+, or the change must wait for corrected upstream Newton metadata.

Minor fixes needed. Posted 1 actionable finding inline.

The full PR diff was reviewed; some supplemental surrounding file context was omitted.

Automated review; human maintainers own approval decisions.

[isaaclab-review-bot]

🟡 Warning · Design Architecture — USD floor conflicts with Newton on wheel install path

project.dependencies now requires usd-core>=26.5 alongside newton[sim,importers]>=1.2.0, whose importer metadata still caps usd-core<26.5 (as stated by the new comment at line 384). The compensating fix lives only in [tool.uv] override-dependencies, which line 93 documents as uv sync only and which is not emitted into wheel metadata. The documented uv pip install <wheel>[extras] path exercised by install_ci/uv_pip/ would then be unresolvable. Constrain the distributed Newton requirement or wait for its metadata fix.

[kellyguo11]

We tried to do this in #6521 but decided against it because it causes a mismatch in versions with kit

[AntoineRichard]

We tried to do this in #6521 but decided against it because it causes a mismatch in versions with kit

Not anymore since Kit moved in this version no? Wasn't that the whole point of migrating to this Kit version?