Bump postcss-svgo from 6.0.3 to 7.0.0

Bumps [postcss-svgo](https://github.com/cssnano/cssnano) from 6.0.3 to 7.0.0.
- [Release notes](https://github.com/cssnano/cssnano/releases)
- [Commits](https://github.com/cssnano/cssnano/compare/postcss-svgo@6.0.3...postcss-svgo@7.0.0)

---
updated-dependencies:
- dependency-name: postcss-svgo
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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