Bump haml from 5.1.2 to 5.2.0 (middleman#2387)

Bumps [haml](https://github.com/haml/haml) from 5.1.2 to 5.2.0.
- [Release notes](https://github.com/haml/haml/releases)
- [Changelog](https://github.com/haml/haml/blob/main/CHANGELOG.md)
- [Commits](haml/haml@v5.1.2...v5.2.0)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Thomas Reynolds <me@tdreyno.com>

Gemfile.lock

@@ -118,7 +118,7 @@ GEM
     execjs (2.7.0)
     fastimage (2.2.0)
     ffi (1.13.1)
-    haml (5.1.2)
+    haml (5.2.0)
       temple (>= 0.8.0)
       tilt
     hamster (3.0.0)