add greedy option

Library/Homebrew/cask/upgrade.rb

@@ -40,9 +40,12 @@ module Cask
       require_sha: nil
     )
 
-    if
       quarantine = true if quarantine.nil?
 
+      if Homebrew::EnvConfig.upgrade_greedy?
+        greedy = true
+      end
+
       outdated_casks = if casks.empty?
         Caskroom.casks(config: Config.from_args(args)).select do |cask|
           cask.outdated?(greedy: greedy, greedy_latest: greedy_latest,

Library/Homebrew/env_config.rb

@@ -347,6 +347,10 @@ module Homebrew
         description: "If set, use Pry for the `brew irb` command.",
         boolean:     true,
       },
+      HOMEBREW_UPGRADE_GREEDY:                         {
+        description: "If set, run `--greedy` with all upgrade commands",
+        boolean:     true,
+      },
       HOMEBREW_SIMULATE_MACOS_ON_LINUX:          {
         description: "If set, running Homebrew on Linux will simulate certain macOS code paths. This is useful " \
                      "when auditing macOS formulae while on Linux.",

Library/Homebrew/env_config.rbi

@@ -229,6 +229,9 @@ module Homebrew::EnvConfig
   sig { returns(T::Boolean) }
   def self.update_to_tag?; end
 
+  sig { returns(T::Boolean) }
+  def self.upgrade_greedy?; end
+
   sig { returns(T::Boolean) }
   def self.verbose?; end