Bump pghero from 2.1.0 to 2.2.0 (#8782)

Bumps [pghero](https://github.com/ankane/pghero) from 2.1.0 to 2.2.0.
- [Release notes](https://github.com/ankane/pghero/releases)
- [Changelog](https://github.com/ankane/pghero/blob/master/CHANGELOG.md)
- [Commits](https://github.com/ankane/pghero/compare/v2.1.0...v2.2.0)

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

Gemfile.lock

@@ -391,7 +391,7 @@ GEM
       equatable (~> 0.5.0)
       tty-color (~> 0.4.0)
     pg (1.0.0)
-    pghero (2.1.0)
+    pghero (2.2.0)
       activerecord
     pkg-config (1.3.0)
     powerpack (0.1.1)
@@ -714,7 +714,7 @@ DEPENDENCIES
   paperclip-av-transcoder (~> 0.6)
   parallel_tests (~> 2.21)
   pg (~> 1.0)
-  pghero (~> 2.1)
+  pghero (~> 2.2)
   pkg-config (~> 1.3)
   posix-spawn!
   premailer-rails