fix(launch): add --no-build-isolation to open_clip and requirements installs

[flagman9040]

What was changed?

Added --no-build-isolation to the open_clip and requirements pip install calls in prepare_environment(), mirroring the existing flag already applied to clip.

Why?

Commit 76759a1 fixed CLIP installation failures (AUTOMATIC1111#17201, AUTOMATIC1111#17284, AUTOMATIC1111#17287) by adding --no-build-isolation to the clip install. The same flag was missing from two other install calls in the same block:

• open_clip — installed from a GitHub ZIP (source distribution)
• requirements_versions.txt — contains jsonmerge==1.8.0 (source distribution, no binary wheel)

With pip 26+, the isolated build environment fails to import setuptools.build_meta for source distributions:

BackendUnavailable: Cannot import 'setuptools.build_meta'
RuntimeError: Couldn't install open_clip.
RuntimeError: Couldn't install requirements.

This causes a complete startup failure on portable/embedded Python 3.10.6 environments (e.g. the sd.webui one-click package) after pip auto-updates to 26+.

Using --no-build-isolation lets pip use the already-installed setuptools==69.5.1 (pinned as line 1 of requirements_versions.txt) directly, avoiding the broken isolated build environment.

How to reproduce

1. Use the sd.webui one-click portable package (embedded Python 3.10.6)
2. Let pip update to 26+ (happens automatically via get-pip.py)
3. Run run.bat — startup fails with BackendUnavailable: Cannot import 'setuptools.build_meta'

How to test

Run run.bat on a portable sd.webui installation with pip 26+ — startup completes successfully.

Checklist

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests