Add Docker to dependabot to Update base image

Signed-off-by: LizenzFass78851 <[email protected]>

Author: LizenzFass78851

.github/dependabot.yml

@@ -2,6 +2,14 @@ version: 2
 updates:
   # Maintain dependencies for GitHub Actions
   - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: saturday
+      time: "10:00"
+    target-branch: master
+  # Maintain dependencies for Docker
+  - package-ecosystem: "docker"
     directory: "/"
     schedule:
       interval: "weekly"

ftl-build/Dockerfile

@@ -1,5 +1,4 @@
-ARG CONTAINER="alpine:3.22"
-FROM ${CONTAINER} AS builder
+FROM alpine:3.22 AS builder
 
 ARG TARGETPLATFORM
 ARG readlineversion=8.2