engineering: use tar+zstd for win32 node_modules cache

[joaomoreno]

Second attempt after #291624 and revert #291740

[Copilot]

Pull request overview

This PR switches the Windows node_modules caching mechanism from 7z compression to tar+zstd compression for improved build performance. This is a second attempt after the initial PR #291624 was reverted in #291740. The change reduces the extraction time from 120-180 seconds to approximately 60 seconds by leveraging tar and zstandard utilities that are bundled in GitHub Actions and Azure Pipelines Windows images.

Changes:

• Replaced 7z.exe commands with tar.exe+zstd for node_modules caching on Windows
• Updated cache file extension from .7z to .tzst
• Updated cache salt timestamp to invalidate old caches

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
build/azure-pipelines/win32/steps/product-build-win32-compile.yml	Updated extraction and creation commands to use tar+zstd instead of 7z
build/azure-pipelines/win32/product-build-win32-node-modules.yml	Updated creation command to use tar+zstd instead of 7z
build/.cachesalt	Updated timestamp to invalidate old 7z-based caches
.github/workflows/pr-win32-test.yml	Updated extraction and creation commands to use tar+zstd instead of 7z
.github/workflows/pr-node-modules.yml	Updated creation command to use tar+zstd instead of 7z

[joaomoreno]

@copilot There's a bug, CI fails when running the Extract node_modules cache:

Run & "C:\Program Files\Git\usr\bin\tar.exe" -xf .build/node_modules_cache/cache.tzst -C . --force-local --use-compress-program "zstd -d"
tar (child): .build/node_modules_cache/cache.tzst: Cannot open: No such file or directory
tar (child): Error is not recoverable: exiting now
/usr/bin/tar: Child returned status 2
/usr/bin/tar: Error is not recoverable: exiting now
Error: Process completed with exit code 1.

[Copilot]

@joaomoreno I've opened a new pull request, #293358, to work on those changes. Once the pull request is ready, I'll request review from you.