Bump lookbook from 2.3.6 to 2.3.7

Bumps [lookbook](https://github.com/ViewComponent/lookbook) from 2.3.6 to 2.3.7.
- [Release notes](https://github.com/ViewComponent/lookbook/releases)
- [Commits](lookbook-hq/lookbook@v2.3.6...v2.3.7)

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

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

Gemfile.lock

@@ -179,7 +179,7 @@ GEM
     loofah (2.24.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
-    lookbook (2.3.6)
+    lookbook (2.3.7)
       activemodel
       css_parser
       htmlbeautifier (~> 1.3)