Bump parallel from 1.19.2 to 1.20.0 (#15115)

Bumps [parallel](https://github.com/grosser/parallel) from 1.19.2 to 1.20.0.
- [Release notes](https://github.com/grosser/parallel/releases)
- [Commits](https://github.com/grosser/parallel/compare/v1.19.2...v1.20.0)

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

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

Gemfile.lock

@@ -391,7 +391,7 @@ GEM
     paperclip-av-transcoder (0.6.4)
       av (~> 0.9.0)
       paperclip (>= 2.5.2)
-    parallel (1.19.2)
+    parallel (1.20.0)
     parallel_tests (3.3.0)
       parallel
     parser (2.7.2.0)
@@ -746,7 +746,7 @@ DEPENDENCIES
   ox (~> 2.13)
   paperclip (~> 6.0)
   paperclip-av-transcoder (~> 0.6)
-  parallel (~> 1.19)
+  parallel (~> 1.20)
   parallel_tests (~> 3.3)
   parslet
   pg (~> 1.2)