fix: bundled extensions (fix package managers)

[Mopsgamer]

Summary

Enables support for pnpm, modern yarn (Berry, ZPM), vlt, bun, and other alternative package managers by properly handling the --no-dependencies flag. This PR fixes a race condition (?) (Promise.all(promises).then(util.flatten)) and ensures the flag is enabled automatically when these managers are detected.

The core logic assumes that extensions using alternative managers are bundling their output; therefore, the node_modules directory does not need to be analyzed via npm list, eliminating "missing dependency" errors.

Features

• Automatic Detection: bun, vlt, pnpm, and yarn (v2+) are detected out of the box.
• Custom Prepublish Commands: Introduced the VSCE_RUN_PREPUBLISH environment variable and vsce.runPrepublish configuration option. This allows for custom commands like bun run vscode:prerelease, which is much faster and actually supports cross-platform scripts properly. You can provide empty VSCE_RUN_PREPUBLISH or false value for vsce.runPrepublish to disable it entirely (probably should remove it).
• When Bun detected, uses bun pm version instead of npm version. So Node-less Bun environments should work.
• For node_modules/** --no-dependecies option will be enabled now if not provided. This makes things faster.
• Fixes #1108.
• Fixes #421.
• Fixes #517.

... Other package manager issues.

I can trip this PR down to remove autodetection and keep