chore(deps): bump github.com/pointfreeco/swift-snapshot-testing (#263)

Bumps [github.com/pointfreeco/swift-snapshot-testing](https://github.com/pointfreeco/swift-snapshot-testing) from 1.15.3 to 1.15.4.
- [Release notes](https://github.com/pointfreeco/swift-snapshot-testing/releases)
- [Commits](pointfreeco/swift-snapshot-testing@1.15.3...1.15.4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]