flutter: add Linux support

Signed-off-by: Patrick Linnane <[email protected]>

Author: izzalDev

Casks/f/flutter.rb

@@ -1,18 +1,26 @@
 cask "flutter" do
   arch arm: "_arm64"
+  os macos: "macos", linux: "linux"
+
+  file_extension = on_system_conditional macos: "zip", linux: "tar.xz"
 
   version "3.35.7"
-  sha256 arm:   "4d7aaadc4893f9216d4e2ecbe0e8fb4213e9bd49d29fd5f441f34fcc05758e2b",
-         intel: "1d9630be94c200877a3799d88db587e3575f88dd05c98bae733756bec0a8ec97"
+  sha256 arm:          "4d7aaadc4893f9216d4e2ecbe0e8fb4213e9bd49d29fd5f441f34fcc05758e2b",
+         intel:        "1d9630be94c200877a3799d88db587e3575f88dd05c98bae733756bec0a8ec97",
+         x86_64_linux: "146df531f9ac6a11a918013c1a70faafc053d4811c8cb69a413fd70748d51c3d"
+
+  on_linux do
+    depends_on arch: :x86_64
+  end
 
-  url "https://storage.googleapis.com/flutter_infra_release/releases/stable/macos/flutter_macos#{arch}_#{version}-stable.zip",
-      verified: "storage.googleapis.com/flutter_infra_release/releases/stable/macos/"
+  url "https://storage.googleapis.com/flutter_infra_release/releases/stable/#{os}/flutter_#{os}#{arch}_#{version}-stable.#{file_extension}",
+      verified: "storage.googleapis.com/flutter_infra_release/releases/stable/#{os}/"
   name "Flutter SDK"
   desc "UI toolkit for building applications for mobile, web and desktop"
   homepage "https://flutter.dev/"
 
   livecheck do
-    url "https://storage.googleapis.com/flutter_infra_release/releases/releases_macos.json"
+    url "https://storage.googleapis.com/flutter_infra_release/releases/releases_#{os}.json"
     strategy :json do |json|
       json["releases"]&.map do |release|
         next if release["channel"] != "stable"