fuse3: define alias for Darwin

Now that macfuse-stubs supports fuse3, update the alias to use it on
Darwin. Also update sshfs-fuse to use the alias now that supports Darwin
and Linux.

pkgs/by-name/ss/sshfs-fuse/common.nix

@@ -15,16 +15,12 @@
   docutils,
   makeWrapper,
   fuse3,
-  macfuse-stubs,
   glib,
   which,
   python3Packages,
   openssh,
 }:
 
-let
-  fuse = if stdenv.hostPlatform.isDarwin then macfuse-stubs.override { isFuse3 = true; } else fuse3;
-in
 stdenv.mkDerivation (finalAttrs: {
   pname = "sshfs-fuse";
   inherit version;
@@ -46,7 +42,7 @@ stdenv.mkDerivation (finalAttrs: {
     makeWrapper
   ];
   buildInputs = [
-    fuse
+    fuse3
     glib
   ];
   nativeCheckInputs = [
@@ -75,7 +71,7 @@ stdenv.mkDerivation (finalAttrs: {
   checkPhase = lib.optionalString (!stdenv.hostPlatform.isDarwin) ''
     # The tests need fusermount:
     mkdir bin
-    cp ${fuse}/bin/fusermount3 bin/fusermount
+    cp ${fuse3}/bin/fusermount3 bin/fusermount
     export PATH=bin:$PATH
     # Can't access /dev/fuse within the sandbox: "FUSE kernel module does not seem to be loaded"
     substituteInPlace test/util.py --replace "/dev/fuse" "/dev/null"

pkgs/top-level/all-packages.nix

@@ -8616,7 +8616,7 @@ with pkgs;
   );
   fuse = fuse2;
   fuse2 = lowPrio (if stdenv.hostPlatform.isDarwin then macfuse-stubs else fusePackages.fuse_2);
-  fuse3 = fusePackages.fuse_3;
+  fuse3 = lowPrio (if stdenv.hostPlatform.isDarwin then macfuse-stubs.override { isFuse3 = true; } else fusePackages.fuse_3);
 
   gpm-ncurses = gpm.override { withNcurses = true; };