chore(deps): update alpine docker tag to v3.21.3

Signed-off-by: red-hat-konflux <126015336+red-hat-konflux[bot]@users.noreply.github.com>

Author: red-hat-konflux[bot]

Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1
 
-ARG BASE_IMAGE=alpine:3.20.3
+ARG BASE_IMAGE=alpine:3.21.3
 ARG JS_IMAGE=node:22-alpine
 ARG JS_PLATFORM=linux/amd64
 ARG GO_IMAGE=golang:1.23.2-alpine