Bump pkg-config from 1.3.9 to 1.4.0 (#12239)

Bumps [pkg-config](https://github.com/ruby-gnome/pkg-config) from 1.3.9 to 1.4.0.
- [Release notes](https://github.com/ruby-gnome/pkg-config/releases)
- [Changelog](https://github.com/ruby-gnome/pkg-config/blob/master/NEWS)
- [Commits](https://github.com/ruby-gnome/pkg-config/compare/1.3.9...1.4.0)

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

Gemfile.lock

@@ -435,7 +435,7 @@ GEM
     pg (1.1.4)
     pghero (2.3.0)
       activerecord (>= 5)
-    pkg-config (1.3.9)
+    pkg-config (1.4.0)
     premailer (1.11.1)
       addressable
       css_parser (>= 1.6.0)
@@ -756,7 +756,7 @@ DEPENDENCIES
   parslet
   pg (~> 1.1)
   pghero (~> 2.3)
-  pkg-config (~> 1.3)
+  pkg-config (~> 1.4)
   posix-spawn!
   premailer-rails
   private_address_check (~> 0.5)