Follow meta schema redirects in tests

It looks like they changed these to redirects:

```
% curl 'http://json-schema.org/draft-07/schema#' -I
HTTP/1.1 301 Moved Permanently
Date: Fri, 13 Oct 2023 21:29:36 GMT
Connection: keep-alive
Cache-Control: max-age=3600
Expires: Fri, 13 Oct 2023 22:29:36 GMT
Location: https://json-schema.org/draft-07/schema
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=4Y8wC8Dh8QkEwNGjF%2FFKlVkfEiFB1hOv3XOnfGJPcIKfna%2FrsYwkURU1zkA5HAgGXRsXFZ3EUCjMOnZiLkXNjDJQ3zvaJJvsS43oAUhIM0uu2CFTfa4QHGRWI%2FpXcULLCqXrAzuUu%2FdG3RU0tFU%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
Vary: Accept-Encoding
CF-Cache-Status: DYNAMIC
Server: cloudflare
CF-RAY: 815aadd5892dcf05-SJC
```

Seems wrong to me, but idk. Added a test helper to resolve redirects
when fetching things.

test/json_schema_test_suite_test.rb

@@ -45,7 +45,7 @@ class JSONSchemaTestSuiteTest < Minitest::Test
       path = Pathname.new(__dir__).join('..', 'JSON-Schema-Test-Suite', 'remotes', uri.path.gsub(/\A\//, ''))
       JSON.parse(path.read)
     else
-      JSON.parse(Net::HTTP.get(uri))
+      JSON.parse(fetch(uri))
     end
   end
 

test/json_schemer_test.rb

@@ -422,7 +422,7 @@ def test_published_meta_schemas
       JSONSchemer::OpenAPI30::Document::SCHEMA
     ].each do |meta_schema|
       id = meta_schema.key?('$id') ? meta_schema.fetch('$id') : meta_schema.fetch('id')
-      assert_equal(meta_schema, JSON.parse(Net::HTTP.get(URI(id))))
+      assert_equal(meta_schema, JSON.parse(fetch(id)))
     end
   end
 

test/test_helper.rb

@@ -12,3 +12,17 @@
 require "json_schemer"
 
 require "minitest/autorun"
+
+def fetch(location, limit = 10)
+  raise if limit.zero?
+  uri = URI(location)
+  response = Net::HTTP.get_response(uri)
+  case response
+  when Net::HTTPSuccess
+    response.body
+  when Net::HTTPRedirection
+    fetch(URI.join(uri, response['Location']), limit - 1)
+  else
+    response.value.body
+  end
+end