prismlauncher: fix darwin

Previously, `glfw-wayland-minecraft` would always be required and the
macOS application would be located at `<store entry>/PrismLauncher.app`,
while certain utilities (i.e. `home-manager`) expect it to be at
`<store entry>/Applications/PrismLauncher.app`

pkgs/games/prismlauncher/default.nix

@@ -60,7 +60,11 @@ stdenv.mkDerivation (finalAttrs: {
     "-DLauncher_BUILD_PLATFORM=nixpkgs"
   ] ++ lib.optionals (msaClientID != null) [ "-DLauncher_MSA_CLIENT_ID=${msaClientID}" ]
   ++ lib.optionals (lib.versionOlder qtbase.version "6") [ "-DLauncher_QT_VERSION_MAJOR=5" ]
-  ++ lib.optionals stdenv.isDarwin [ "-DINSTALL_BUNDLE=nodeps" "-DMACOSX_SPARKLE_UPDATE_FEED_URL=''" ];
+  ++ lib.optionals stdenv.isDarwin [
+    "-DINSTALL_BUNDLE=nodeps"
+    "-DMACOSX_SPARKLE_UPDATE_FEED_URL=''"
+    "-DCMAKE_INSTALL_PREFIX=${placeholder "out"}/Applications/"
+  ];
 
   postUnpack = ''
     rm -rf source/libraries/libnbtplusplus

pkgs/games/prismlauncher/wrapper.nix

@@ -70,7 +70,7 @@ symlinkJoin {
   ]
   ++ lib.optional (lib.versionAtLeast qtbase.version "6" && stdenv.isLinux) qtwayland;
 
-  waylandPreExec = ''
+  waylandPreExec = lib.optionalString withWaylandGLFW ''
     if [ -n "$WAYLAND_DISPLAY" ]; then
       export LD_LIBRARY_PATH=${lib.getLib glfw-wayland-minecraft}/lib:"$LD_LIBRARY_PATH"
     fi