Bump next from 9.5.5-canary.1 to 9.5.6-canary.4
Bump next from 9.5.5-canary.1 to 9.5.6-canary.4

Bumps [next](https://github.com/vercel/next.js) from 9.5.5-canary.1 to 9.5.6-canary.4.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](https://github.com/vercel/next.js/compare/v9.5.5-canary.1...v9.5.6-canary.4)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
conveyal/analysis-ui,conveyal/analysis-ui,conveyal/analysis-ui