Make http_io honor HTTP(S)_PROXY environment.

changelogs/unreleased/fix-http-proxy.yml

+---
+title: Fixed HTTP_PROXY environment not honored when reading remote traces.
+merge_request: 19282
+author: NLR
+type: fixed

lib/gitlab/ci/trace/http_io.rb

@@ -148,7 +148,7 @@ module Gitlab
 
         def get_chunk
           unless in_range?
-            response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: uri.scheme == 'https') do |http|
+            response = Net::HTTP.start(uri.hostname, uri.port, proxy_from_env: true, use_ssl: uri.scheme == 'https') do |http|
               http.request(request)
             end