Bump statesman from 10.0.0 to 12.1.0

Bumps [statesman](https://github.com/gocardless/statesman) from 10.0.0 to 12.1.0.
- [Release notes](https://github.com/gocardless/statesman/releases)
- [Changelog](https://github.com/gocardless/statesman/blob/master/CHANGELOG.md)
- [Commits](gocardless/statesman@v10.0.0...v12.1.0)

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

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

Author: dependabot[bot]

Gemfile

@@ -53,7 +53,7 @@ gem "sentry-sidekiq"
 gem "sidekiq"
 gem "sitemap_generator"
 gem "stackprof"
-gem "statesman", "= 10.0.0" # Pinned due to bug https://github.com/gocardless/statesman/issues/509
+gem "statesman", "12.1.0" # Pinned due to bug https://github.com/gocardless/statesman/issues/509
 gem "terser"
 gem "turbolinks"
 gem "uglifier"

Gemfile.lock

@@ -695,7 +695,7 @@ GEM
     standard-rails (0.2.0)
       lint_roller (~> 1.0)
       rubocop-rails (~> 2.20.2)
-    statesman (10.0.0)
+    statesman (12.1.0)
     stringio (3.1.5)
     terser (1.2.5)
       execjs (>= 0.3.0, < 3)
@@ -849,7 +849,7 @@ DEPENDENCIES
   stackprof
   standard
   standard-rails
-  statesman (= 10.0.0)
+  statesman (= 12.1.0)
   terser
   timecop
   turbolinks