ci: move patches to patches directory

Group all patches in a directory.
Improve organization to organize the current and future patches.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Sergi Blanch Torné <sergi.blanch.torne@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20019>

.gitlab-ci/container/build-skqp.sh

@@ -49,7 +49,7 @@ download_skia_source() {
 set -ex
 
 SCRIPT_DIR=$(realpath "$(dirname "$0")")
-SKQP_PATCH_DIR="${SCRIPT_DIR}"
+SKQP_PATCH_DIR="${SCRIPT_DIR}/patches"
 BASE_ARGS_GN_FILE="${SCRIPT_DIR}/build-skqp_base.gn"
 
 SKQP_ARCH=${SKQP_ARCH:-x64}