config: add x11proto dependency for libxau and SDDM

- Add x11proto to redbear-full.toml package list
- libxau recipe updated with x11proto dependency and custom build script
- Fixes libxau build failure: 'Package xproto was not found'

recipes/dev/python312/recipe.toml

@@ -34,12 +34,13 @@ if [ "$TARGET" != "$COOKBOOK_HOST_TARGET" ]; then
         --disable-ipv6
         --host=${GNU_TARGET}
         --build="$ARCH"
-        --with-build-python="${COOKBOOK_TOOLCHAIN}/usr/bin/python3.12"
+        --with-build-python="/tmp/python312/bin/python3.12"
         --with-ensurepip=install
         --disable-test-modules
         --with-ssl-default-suites=openssl
         ac_cv_file__dev_ptmx=no
         ac_cv_file__dev_ptc=no
+        ac_cv_exeext=""
     )
 else
     COOKBOOK_CONFIGURE_FLAGS=(--prefix=/usr)