bridge-js command fails on 6.3: `no such module 'SwiftBasicFormat'`

on macOS with 6.3-snapshot-2026-02-27

```sh
$ swift package bridge-js

JavaScriptKit/Sources/BridgeJSTool/BridgeJSCore/ClosureCodegen.swift:1:8: error: no such module 'SwiftBasicFormat'
  1 | import SwiftBasicFormat
    |        `- error: no such module 'SwiftBasicFormat'
  2 | import SwiftSyntax
  3 | import SwiftSyntaxBuilder
```