Bump webmock from 3.19.1 to 3.20.0

Bumps [webmock](https://github.com/bblimke/webmock) from 3.19.1 to 3.20.0.
- [Changelog](https://github.com/bblimke/webmock/blob/master/CHANGELOG.md)
- [Commits](bblimke/webmock@v3.19.1...v3.20.0)

---
updated-dependencies:
- dependency-name: webmock
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -97,7 +97,8 @@ GEM
     coderay (1.1.3)
     concurrent-ruby (1.2.3)
     connection_pool (2.4.1)
-    crack (0.4.5)
+    crack (0.4.6)
+      bigdecimal
       rexml
     crass (1.0.6)
     database_cleaner (2.0.2)
@@ -174,7 +175,7 @@ GEM
       govuk_app_config (>= 1.1)
       redis-namespace (~> 1.6)
       sidekiq (~> 6.5, >= 6.5.12)
-    hashdiff (1.0.1)
+    hashdiff (1.1.0)
     hashie (5.0.0)
     http-accept (1.7.0)
     http-cookie (1.0.5)
@@ -682,7 +683,7 @@ GEM
       activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
       railties (>= 6.0.0)
-    webmock (3.19.1)
+    webmock (3.20.0)
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)