Add CODEOWNERS routing Dependabot Ruby PRs to apps-infra-tooling

Author: mokagio

.github/CODEOWNERS

@@ -0,0 +1,6 @@
+# Route Dependabot Ruby dependency PRs to the tooling team. See AINFRA-2437.
+Gemfile*       @wordpress-mobile/apps-infra-tooling
+*.gemspec      @wordpress-mobile/apps-infra-tooling
+.ruby-version  @wordpress-mobile/apps-infra-tooling
+.bundle/       @wordpress-mobile/apps-infra-tooling
+.rubocop*.yml  @wordpress-mobile/apps-infra-tooling