build(deps-dev): bump pytest-regressions from 2.5.0 to 2.6.0

Bumps [pytest-regressions](https://github.com/ESSS/pytest-regressions) from 2.5.0 to 2.6.0.
- [Release notes](https://github.com/ESSS/pytest-regressions/releases)
- [Changelog](https://github.com/ESSS/pytest-regressions/blob/master/CHANGELOG.rst)
- [Commits](ESSS/pytest-regressions@2.5.0...v2.6.0)

---
updated-dependencies:
- dependency-name: pytest-regressions
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]