chore(deps): update dependency openapi_first to v3

Author: renovate[bot]

Gemfile

@@ -40,7 +40,7 @@ group :test do
   gem "approvals", ">=0.0.24", "<1.0.0"
   gem "tzinfo", "~>2.0"
   gem "faraday-retry", "~>2.0"
-  gem "openapi_first", "~>2.0"
+  gem "openapi_first", "~>3.0"
 end
 
 group :pg, optional: true do