Bump pghero from 2.7.0 to 2.7.2 (#14786)

Bumps [pghero](https://github.com/ankane/pghero) from 2.7.0 to 2.7.2.
- [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/v2.7.0...v2.7.2)

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

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

Gemfile.lock

@@ -406,7 +406,7 @@ GEM
     pastel (0.8.0)
       tty-color (~> 0.5)
     pg (1.2.3)
-    pghero (2.7.0)
+    pghero (2.7.2)
       activerecord (>= 5)
     pkg-config (1.4.2)
     posix-spawn (0.3.15)