gcc: only apply patches on macOS

Author: cho-m

Formula/g/gcc.rb

@@ -13,14 +13,18 @@ class Gcc < Formula
     # Branch from the Darwin maintainer of GCC, with a few generic fixes and
     # Apple Silicon support, located at https://github.com/iains/gcc-14-branch
     patch do
-      url "https://raw.githubusercontent.com/Homebrew/formula-patches/f30c309442a60cfb926e780eae5d70571f8ab2cb/gcc/gcc-14.2.0-r2.diff"
-      sha256 "6c0a4708f35ccf2275e6401197a491e3ad77f9f0f9ef5761860768fa6da14d3d"
+      on_macos do
+        url "https://raw.githubusercontent.com/Homebrew/formula-patches/f30c309442a60cfb926e780eae5d70571f8ab2cb/gcc/gcc-14.2.0-r2.diff"
+        sha256 "6c0a4708f35ccf2275e6401197a491e3ad77f9f0f9ef5761860768fa6da14d3d"
+      end
     end
 
     # Fix for macOS 15.4 SDK issue https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119590
     patch do
-      url "https://github.com/iains/gcc-14-branch/commit/efb88ebe0a6886f816c0d037df33df6556544ad6.patch?full_index=1"
-      sha256 "4077af416eaf40a968e4b9d382aeb6470c2b79f09a52da2dd6aa91ace7af5c87"
+      on_macos do
+        url "https://github.com/iains/gcc-14-branch/commit/efb88ebe0a6886f816c0d037df33df6556544ad6.patch?full_index=1"
+        sha256 "4077af416eaf40a968e4b9d382aeb6470c2b79f09a52da2dd6aa91ace7af5c87"
+      end
     end
   end