fix: skip watchPackageDataPlugin for worker builds

[bluwy]

Description

The actual fix instead of #14751 (the PR did nothing)

The issue was that this.addWatchFile was brought outside the scope of buildStart by the plugin:

vite/packages/vite/src/node/packages.ts

Lines 243 to 247 in 521ca58

	buildStart() {
	watchFile = this.addWatchFile.bind(this)
	watchQueue.forEach(watchFile)
	watchQueue.clear()
	},

So Rollup wasn't able to catch the error and pass it to onwarn for filtering (and I also think it should be onLog now). The error is invoked outside the scope:

vite/packages/vite/src/node/packages.ts

Lines 233 to 239 in 521ca58

	packageCache.set = (id, pkg) => {
	if (!isInNodeModules(pkg.dir) && !watchedDirs.has(pkg.dir)) {
	watchedDirs.add(pkg.dir)
	watchFile(path.join(pkg.dir, 'package.json'))
	}
	return setPackageData(id, pkg)
	}

Additional context

It's a bit hard to reproduce this so I thought the other PR fixed it. But I think this PR should fix it for real now.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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