Unbiome (#2776)

Biome as it is now didn't work out for us 😢 

Summary for posterity:

* it IS much, much faster, fast enough to skip any sort of caching
* we couldn't fully replace Prettier just yet. We use Prettier
programmatically to format code in docs, and Biome's JS interface is
officially alpha and [had legacy peer deps
set](https://github.com/biomejs/biome/pull/1756) (which would fail our
CI build as we don't allow installation warnings)
* ternary formatting differs from Prettier, leading to a large diff
https://github.com/biomejs/biome/issues/1661
* import sorting differs from Prettier's
`prettier-plugin-organize-imports`, making the diff even bigger
* the deal breaker is a multi-second delay on saving large files (for us
it's
[Editor.ts](https://github.com/tldraw/tldraw/blob/main/packages/editor/src/lib/editor/Editor.ts))
in VSCode when import sorting is enabled. There is a seemingly relevant
Biome issue where I posted a small summary of our findings:
https://github.com/biomejs/biome/issues/1569#issuecomment-1930411623

Further actions:

* reevaluate in a few months as Biome matures

### Change Type

- [x] `internal` — Any other changes that don't affect the published
package

scripts/lint.ts

@@ -4,6 +4,7 @@ import { exec } from './lib/exec'
 import { REPO_ROOT, readFileIfExists } from './lib/file'
 
 const ESLINT_EXTENSIONS = ['js', 'jsx', 'ts', 'tsx']
+const PRETTIER_EXTENSIONS = ['js', 'jsx', 'ts', 'tsx', 'json']
 
 async function main() {
 	const shouldFix = process.argv.includes('--fix')
@@ -26,10 +27,19 @@ async function main() {
 		files.push(file)
 	}
 
+	let prettierFiles = PRETTIER_EXTENSIONS.flatMap((ext) => filesByExtension.get(ext) ?? [])
 	let eslintFiles = ESLINT_EXTENSIONS.flatMap((ext) => filesByExtension.get(ext) ?? [])
 
 	const relativeCwd = path.relative(REPO_ROOT, process.cwd())
 
+	const prettierIgnoreFile = await readFileIfExists(path.join(REPO_ROOT, '.prettierignore'))
+	if (prettierIgnoreFile) {
+		prettierFiles = prettierFiles
+			.map((f) => path.join(relativeCwd, f))
+			.filter(ignore().add(prettierIgnoreFile).createFilter())
+			.map((f) => path.relative(relativeCwd, f))
+	}
+
 	const eslintIgnoreFile = await readFileIfExists(path.join(REPO_ROOT, '.eslintignore'))
 	if (eslintIgnoreFile) {
 		eslintFiles = eslintFiles
@@ -39,6 +49,14 @@ async function main() {
 	}
 
 	try {
+		await exec('yarn', [
+			'run',
+			'-T',
+			'prettier',
+			shouldFix ? '--write' : '--check',
+			'--cache',
+			...prettierFiles,
+		])
 		await exec('yarn', [
 			'run',
 			'-T',