release: Bump extension version to 2026.10.0 (#26225)

## Summary
- Bump the extension from 2026.9.0-dev to the stable release candidate
2026.10.0.
- Update package-lock.json with version-only changes; dependencies are
unchanged.
- Retain the existing pet release/2026.12 reference as requested.

## Validation
- Verified package.json and both lockfile version fields agree on
2026.10.0.
- Compared parsed manifests against HEAD and confirmed no non-version
changes.
- git diff --check passed.

The pre-release pipeline may fail temporarily because this sets an even
stable version on main. After merging and creating release/2026.10,
restore main to 2026.11.0-dev before the next nightly pre-release.

Copilot-Session: 75f5808b-7a7d-4fd4-a1ee-b4ac8c340d36

Update release/2026.8 with latest changes from main (#26203)

Fast-forwards the release branch with the latest main change, updating
the stable pipeline to consume PET from release/2026.12. The extension
version remains 2026.8.0.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

release: Prevent virtualenv redirect from occupying .venv (#26168)

## Why
Backport of
[#26167](#26167) for the
2026.6 release branch. [virtualenv
21.12](https://github.com/pypa/virtualenv/releases/tag/21.12.0) began
writing a `.venv` redirect file when creating `.virtualenv` in a project
with `pyproject.toml`. The following `python -m venv .venv` then cannot
create the separate stdlib venv directory, breaking the release branch's
Windows and Linux venv jobs.

## Change
Pass `--no-venv-redirect` when creating `.virtualenv` so the existing
`.virtualenv` and `.venv` tests continue to use their original, separate
paths. Exit immediately if stdlib venv creation fails.

## Windows unit-test investigation
The Windows `ts-unit` job also intermittently failed on the first Native
Python Finder refresh while the subsequent refresh succeeded. The
locator-output diagnostic reproduced the failure: Pet logged `Skipping
refresh state sync for stale generation 0 because current generation is
1` and returned no environments. The finder had launched a configure
request in its constructor without awaiting it, while its first refresh
launched another configure and could start before the first completed.
Pet suppresses environment notifications from stale configuration
generations. Remove the redundant constructor configure; the first
refresh already configures and awaits completion before sending the
refresh request. The existing non-empty assertion is unchanged and still
includes the locator log on failure.

The release branch's Build workflow must pass after this lands before
releasing.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

bump to release v 2026.4.0 (#25852)

Bump version to 2026.2.0 in package.json (#25801)

update version to 2026.0.0 release version (#25715)

bump to point release v2025.20.1 (#25672)

bump version to 2025.20.0 (#25634)

bump to release v 2025.18.0 (#25576)

bump to v2025.16.0 (#25497)