Bump arrayvec from 0.7.4 to 0.7.6

Bumps [arrayvec](https://github.com/bluss/arrayvec) from 0.7.4 to 0.7.6.
- [Release notes](https://github.com/bluss/arrayvec/releases)
- [Changelog](https://github.com/bluss/arrayvec/blob/master/CHANGELOG.md)
- [Commits](bluss/arrayvec@0.7.4...0.7.6)

---
updated-dependencies:
- dependency-name: arrayvec
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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