chore(deps): bump @open-rpc/meta-schema from 1.12.5 to 1.12.6

Bumps [@open-rpc/meta-schema](https://github.com/open-rpc/schema) from 1.12.5 to 1.12.6.
- [Release notes](https://github.com/open-rpc/schema/releases)
- [Changelog](https://github.com/open-rpc/meta-schema/blob/master/CHANGELOG.md)
- [Commits](open-rpc/meta-schema@1.12.5...1.12.6)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>