gnu: Use default kernel headers again.

The default headers got updated to 6.12.17 in
93d9cd7c22
so the manual overrides are no longer necessary.

Fixes https://issues.guix.gnu.org/72119.

* gnu/packages/linux.scm (libbpf)[native-inputs]: Remove linux-libre-headers-latest.
* gnu/packages/gnome.scm (mutter)[inputs]: Remove linux-libre-headers-6.1
* gnu/packages/wm.scm (hyprland)[inputs]: Remove linux-libre-headers-6.14

Change-Id: I374cb190396d6af2669c02cf29626b3851186d41

gnu/packages/gnome.scm

@@ -8247,7 +8247,6 @@ to display dialog boxes from the commandline and shell scripts.")
            libxkbfile
            libxrandr
            libxtst
-           linux-libre-headers-6.1      ; for dma_buf_export_sync_file
            pipewire
            startup-notification
            sysprof

gnu/packages/linux.scm

@@ -11137,7 +11137,7 @@ persistent over reboots.")
                                                  ;; user API (uAPI) headers.
                                                  "install_uapi_headers")
                                            make-flags)))))))))
-    (native-inputs (list linux-libre-headers-latest pkg-config))
+    (native-inputs (list pkg-config))
     (propagated-inputs (list elfutils zlib)) ;in Requires.private of libbpf.pc
     (home-page "https://github.com/libbpf/libbpf")
     (synopsis "BPF CO-RE (Compile Once – Run Everywhere)")

gnu/packages/wm.scm

@@ -444,7 +444,6 @@ loginctl commands (lock/unlock/before-sleep) and inhibit.")
            udis86
            wayland
            wayland-protocols
-           linux-libre-headers-6.14
            xcb-util-errors
            xcb-util-wm
            xorg-server-xwayland))