Bump sanitize from 5.2.1 to 6.0.0

Bumps [sanitize](https://github.com/rgrove/sanitize) from 5.2.1 to 6.0.0.
- [Release notes](https://github.com/rgrove/sanitize/releases)
- [Changelog](https://github.com/rgrove/sanitize/blob/main/HISTORY.md)
- [Commits](rgrove/sanitize@v5.2.1...v6.0.0)

---
updated-dependencies:
- dependency-name: sanitize
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Gemfile.lock

@@ -187,7 +187,7 @@ GEM
     marcel (1.0.1)
     method_source (1.0.0)
     mini_mime (1.1.0)
-    mini_portile2 (2.5.1)
+    mini_portile2 (2.6.1)
     minitest (5.14.4)
     msgpack (1.3.3)
     multi_json (1.15.0)
@@ -200,11 +200,9 @@ GEM
     nested_form (0.3.2)
     newrelic_rpm (6.14.0)
     nio4r (2.5.7)
-    nokogiri (1.11.3)
-      mini_portile2 (~> 2.5.0)
+    nokogiri (1.12.3)
+      mini_portile2 (~> 2.6.1)
       racc (~> 1.4)
-    nokogumbo (2.0.4)
-      nokogiri (~> 1.8, >= 1.8.4)
     oauth (0.5.6)
     oauth2 (1.4.4)
       faraday (>= 0.8, < 2.0)
@@ -354,10 +352,9 @@ GEM
       rubocop (>= 0.53.0)
     ruby-progressbar (1.11.0)
     ruby2_keywords (0.0.2)
-    sanitize (5.2.1)
+    sanitize (6.0.0)
       crass (~> 1.0.2)
-      nokogiri (>= 1.8.0)
-      nokogumbo (~> 2.0)
+      nokogiri (>= 1.12.0)
     sassc (2.4.0)
       ffi (~> 1.9)
     sassc-rails (2.1.2)