chore(archlinux-syncrepo): update alpine docker tag to v3.21.3

Author: renovate-bot

containers/archlinux-syncrepo/Dockerfile

@@ -1,8 +1,8 @@
 # platforms: linux/amd64,linux/386,linux/arm64,linux/arm/v7,linux/arm/v6,linux/ppc64le,linux/s390x
 # app_version: 1.0.0
-# revision: 20
+# revision: 21
 # description: Arch Linux syncrepo mirror synchronization script
-FROM        alpine:3.21.2@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099 AS patch
+FROM        alpine:3.21.3@sha256:a8560b36e8b8210634f77d9f7f9efd7ffa463e380b75e2e74aff4511df3ef88c AS patch
 
 ARG         SYNCREPO_VERSION=4fe427a2
 
@@ -19,7 +19,7 @@ RUN         patch /syncrepo /syncrepo.patch
 
 
 
-FROM        alpine:3.21.2@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099
+FROM        alpine:3.21.3@sha256:a8560b36e8b8210634f77d9f7f9efd7ffa463e380b75e2e74aff4511df3ef88c
 
 # renovate: datasource=repology depName=alpine_3_21/rsync versioning=loose
 ARG         RSYNC_VERSION="3.4.0-r0"