Bump sass from 3.7.2 to 3.7.3

Bumps [sass](https://github.com/sass/ruby-sass) from 3.7.2 to 3.7.3.
- [Release notes](https://github.com/sass/ruby-sass/releases)
- [Commits](sass/ruby-sass@3.7.2...3.7.3)

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

Author: dependabot-support

Gemfile.lock

@@ -28,7 +28,7 @@ GEM
     execjs (2.7.0)
     faraday (0.15.4)
       multipart-post (>= 1.2, < 3)
-    ffi (1.9.25)
+    ffi (1.10.0)
     forwardable-extended (2.6.0)
     gemoji (3.0.0)
     github-pages (193)
@@ -233,7 +233,7 @@ GEM
     ruby_dep (1.5.0)
     rubyzip (1.2.2)
     safe_yaml (1.0.4)
-    sass (3.7.2)
+    sass (3.7.3)
       sass-listen (~> 4.0.0)
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)