buildMozillaMach: revert apple SDK bump to 26.1 (#468743)

pkgs/build-support/build-mozilla-mach/default.nix

@@ -45,6 +45,7 @@ in
   pkgs,
   stdenv,
   patchelf,
+  fetchpatch,
 
   # build time
   autoconf,
@@ -328,6 +329,16 @@ buildStdenv.mkDerivation {
       # https://hg-edge.mozilla.org/mozilla-central/rev/aa8a29bd1fb9
       ./139-wayland-drag-animation.patch
     ]
+    # Revert apple sdk bump to 26.1
+    ++
+      lib.optionals (lib.versionAtLeast version "146" && lib.versionOlder apple-sdk_26.version "26.1")
+        [
+          (fetchpatch {
+            url = "https://github.com/mozilla-firefox/firefox/commit/c1cd0d56e047a40afb2a59a56e1fd8043e448e05.patch";
+            hash = "sha256-bFHLy3b0jOcROqltIwHwSAqWYve8OZHbiPMOdhLUCLc=";
+            revert = true;
+          })
+        ]
     ++ extraPatches;
 
   postPatch = ''