build(deps): bump postcss-merge-longhand from 7.0.1 to 7.0.2

Bumps [postcss-merge-longhand](https://github.com/cssnano/cssnano) from 7.0.1 to 7.0.2.
- [Release notes](https://github.com/cssnano/cssnano/releases)
- [Commits](https://github.com/cssnano/cssnano/compare/[email protected]@7.0.2)

---
updated-dependencies:
- dependency-name: postcss-merge-longhand
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]