build(deps-dev): bump mockery/mockery from 1.6.12 to 1.6.15

Bumps [mockery/mockery](https://github.com/mockery/mockery) from 1.6.12 to 1.6.15.
- [Release notes](https://github.com/mockery/mockery/releases)
- [Changelog](https://github.com/mockery/mockery/blob/1.6.x/CHANGELOG.md)
- [Commits](mockery/mockery@1.6.12...1.6.15)

---
updated-dependencies:
- dependency-name: mockery/mockery
  dependency-version: 1.6.15
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]