hyprland: add libexecinfo on musl (#253472)

pkgs/applications/window-managers/hyprwm/hyprland/default.nix

···
 , hyprland-protocols
 , jq
 , libdrm
+, libexecinfo
 , libinput
 , libxcb
 , libxkbcommon
···
       pciutils
       (wlroots.override { inherit enableNvidiaPatches; })
     ]
+    ++ lib.optionals stdenv.hostPlatform.isMusl [ libexecinfo ]
     ++ lib.optionals enableXWayland [ libxcb xcbutilwm xwayland ]
     ++ lib.optionals withSystemd [ systemd ];