Bump font-awesome-sass from 4.7.0 to 6.5.1

Bumps [font-awesome-sass](https://github.com/FortAwesome/font-awesome-sass) from 4.7.0 to 6.5.1.
- [Release notes](https://github.com/FortAwesome/font-awesome-sass/releases)
- [Commits](https://github.com/FortAwesome/font-awesome-sass/commits)

---
updated-dependencies:
- dependency-name: font-awesome-sass
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Gemfile.lock

@@ -64,8 +64,8 @@ GEM
     fog-xml (0.1.4)
       fog-core
       nokogiri (>= 1.5.11, < 2.0.0)
-    font-awesome-sass (4.7.0)
-      sass (>= 3.2)
+    font-awesome-sass (6.5.1)
+      sassc (~> 2.0)
     formatador (1.1.0)
     haml (5.2.2)
       temple (>= 0.8.0)
@@ -197,11 +197,6 @@ GEM
     rexml (3.2.6)
     ruby-progressbar (1.13.0)
     ruby-rc4 (0.1.5)
-    sass (3.7.4)
-      sass-listen (~> 4.0.0)
-    sass-listen (4.0.0)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
     sassc (2.4.0)
       ffi (~> 1.9)
     servolux (0.13.0)