Swift: Bump github.com/pointfreeco/swift-snapshot-testing

Bumps the swift-dependencies group with 1 update: [github.com/pointfreeco/swift-snapshot-testing](https://github.com/pointfreeco/swift-snapshot-testing).


Updates `github.com/pointfreeco/swift-snapshot-testing` from 1.18.0 to 1.18.1
- [Release notes](https://github.com/pointfreeco/swift-snapshot-testing/releases)
- [Commits](pointfreeco/swift-snapshot-testing@1.18.0...1.18.1)

---
updated-dependencies:
- dependency-name: github.com/pointfreeco/swift-snapshot-testing
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: swift-dependencies
...

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

Author: dependabot[bot]