Always use CurlDownloadStrategy for legacy patches

Fixes Homebrew/homebrew#27671.

Library/Homebrew/patch.rb

@@ -136,6 +136,7 @@ class LegacyPatch < ExternalPatch
   def initialize(strip, url)
     super(strip)
     resource.url = url
+    resource.download_strategy = CurlDownloadStrategy
   end
 
   def owner= owner

Library/Homebrew/resource.rb

@@ -9,7 +9,7 @@ class Resource
   include FileUtils
 
   attr_reader :checksum, :mirrors, :specs, :using
-  attr_writer :url, :checksum, :version
+  attr_writer :url, :checksum, :version, :download_strategy
 
   # Formula name must be set after the DSL, as we have no access to the
   # formula name before initialization of the formula