Bumps [proc-macro-nested](https://github.com/dtolnay/proc-macro-hack) from 0.1.4 to 0.1.6. - [Release notes](https://github.com/dtolnay/proc-macro-hack/releases) - [Commits](https://github.com/dtolnay/proc-macro-hack/commits) Signed-off-by: dependabot-preview[bot] <support@dependabot.com>