Bump pinia from 2.0.11 to 2.1.6

Bumps [pinia](https://github.com/vuejs/pinia) from 2.0.11 to 2.1.6.
- [Release notes](https://github.com/vuejs/pinia/releases)
- [Commits](https://github.com/vuejs/pinia/compare/[email protected]@2.1.6)

---
updated-dependencies:
- dependency-name: pinia
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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