build(deps-dev): bump eslint-plugin-flowtype in /token/js (#1575)

Bumps [eslint-plugin-flowtype](https://github.com/gajus/eslint-plugin-flowtype) from 5.3.1 to 5.6.0.
- [Release notes](https://github.com/gajus/eslint-plugin-flowtype/releases)
- [Commits](gajus/eslint-plugin-flowtype@v5.3.1...v5.6.0)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>