build(deps-dev): bump backstopjs from 6.3.1 to 6.3.2

Bumps [backstopjs](https://github.com/garris/backstopjs) from 6.3.1 to 6.3.2.
- [Release notes](https://github.com/garris/backstopjs/releases)
- [Changelog](https://github.com/garris/BackstopJS/blob/master/changelog.md)
- [Commits](https://github.com/garris/backstopjs/commits/v6.3.2)

---
updated-dependencies:
- dependency-name: backstopjs
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package-lock.json

@@ -72,7 +72,7 @@
     "@pattern-lab/starterkit-handlebars-demo": "^6.1.0",
     "@pattern-lab/uikit-workshop": "^6.1.0",
     "autoprefixer": "^10.4.16",
-    "backstopjs": "^6.3.1",
+    "backstopjs": "^6.3.2",
     "cpr": "^3.0.1",
     "cssnano": "^6.0.2",
     "details-element-polyfill": "^2.4.0",