Resource, CurlDownloadStrategy: Deduplicate the curl HEAD requests

Fixes #5357

* Eliminates getting a new strategy instance via Resource methods
* only call resolve_url_basename_time once and store the time result as
an instance variable for reuse

Library/Homebrew/download_strategy.rb

@@ -329,12 +329,14 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
   private
 
   def resolved_url_and_basename
-    return @resolved_url_and_basename if defined?(@resolved_url_and_basename)
     resolved_url, basename, = resolve_url_basename_time(url)
-    @resolved_url_and_basename = [resolved_url, basename]
+    [resolved_url, basename]
   end
 
   def resolve_url_basename_time(url)
+    @resolved_info_cache ||= {}
+    return @resolved_info_cache[url] if @resolved_info_cache.include?(url)
+
     if ENV["HOMEBREW_ARTIFACT_DOMAIN"]
       url = url.sub(%r{^((ht|f)tps?://)?}, ENV["HOMEBREW_ARTIFACT_DOMAIN"].chomp("/") + "/")
     end
@@ -373,7 +375,7 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
 
     basename = filenames.last || parse_basename(redirect_url)
 
-    [redirect_url, basename, time]
+    @resolved_info_cache[url] = [redirect_url, basename, time]
   end
 
   def _fetch(url:, resolved_url:)

Library/Homebrew/resource.rb

@@ -35,8 +35,8 @@ class Resource
   end
 
   def downloader
-    download_strategy.new(url, download_name, version,
-                          mirrors: mirrors.dup, **specs)
+    @downloader ||= download_strategy.new(url, download_name, version,
+                                          mirrors: mirrors.dup, **specs)
   end
 
   # Removes /s from resource names; this allows go package names