feat(build): Set explicit image versions in keycloakify docker file

keycloak/keycloakify/Dockerfile

@@ -1,15 +1,19 @@
-FROM node:latest as builder
+FROM node:21-bookworm as builder
 
 USER root
 RUN apt-get update && apt-get install -y maven
 
+RUN mvn --version
+
+RUN yarn versions
+
 WORKDIR /app
 COPY package.json yarn.lock ./
 RUN yarn
 COPY . .
 RUN yarn build-keycloak-theme
 
-FROM alpine:latest
+FROM alpine:3.19
 RUN mkdir /output
 COPY --from=builder /app/build_keycloak/target/*.jar /output/
 RUN apk add --no-cache wget curl