Pull request 2570: AGDNS-3555-use-buildx-again

Squashed commit of the following:

commit 825a91a62f82c6597e98690f739116b12005651f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Jan 29 16:31:13 2026 +0300

    scripts: use buildx

scripts/make/build-docker.sh

@@ -108,6 +108,7 @@ docker_build_opt_tag() {
 	set -- \
 		"$@" \
 		docker \
+		buildx \
 		build \
 		--build-arg BUILD_DATE="$build_date" \
 		--build-arg DIST_DIR="$dist_dir" \