precompress logic should live in Kit, not adapters

[Rich-Harris]

Describe the problem

There's no reason for both of these to exist:

kit/packages/adapter-node/index.js

Lines 73 to 91 in 225c1ce

	/**
	* @param {string} directory
	*/
	async function compress(directory) {
	if (!existsSync(directory)) {
	return;
	}
	const files = await glob('**/*.{html,js,json,css,svg,xml,wasm}', {
	cwd: directory,
	dot: true,
	absolute: true,
	filesOnly: true
	});
	await Promise.all(
	files.map((file) => Promise.all([compress_file(file, 'gz'), compress_file(file, 'br')]))
	);
	}

kit/packages/adapter-static/index.js

Lines 49 to 63 in 225c1ce

	/**
	* @param {string} directory
	*/
	async function compress(directory) {
	const files = await glob('**/*.{html,js,json,css,svg,xml,wasm}', {
	cwd: directory,
	dot: true,
	absolute: true,
	filesOnly: true
	});
	await Promise.all(
	files.map((file) => Promise.all([compress_file(file, 'gz'), compress_file(file, 'br')]))
	);
	}

Describe the proposed solution

The logic should live in Kit itself — adapters should be able to do this sort of thing:

if (options.precompress) {
  await builder.precompress(dir);
}

Alternatives considered

No response

Importance

nice to have

Additional Information

No response