fix(fantom): declare metro dependencies for pnpm nodeLinker

`@react-native/fantom` imports `metro` and `metro-babel-transformer`
(e.g. `import type {RunServerResult} from 'metro'`) but never declared
them. Under the old hoisted node-modules layout they resolved to the
workspace's metro 0.83.x; under Yarn's pnpm nodeLinker (#3010) the
package instead resolves `metro` to 0.82.5 (pulled in transitively by the
unused `metro-memory-fs@^0.82.5`), which predates the `RunServerResult`
export, and cannot resolve `metro-babel-transformer` at all. Flow then
fails the JavaScript Tests job:

    globalTeardown.js: Cannot import `RunServerResult` ... no `RunServerResult`
      export in `metro`
    metro-babel-transformer.flow.js: Cannot resolve module
      `metro-babel-transformer`

Declare both at `^0.83.3` (matching the rest of the monorepo) so pnpm links
the correct versions. Verified locally: `yarn flow check` reports 0 errors.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>