module: Switch to using an Alpine base image

The Ubuntu base image no longer works for RaspberryPi
builds, and the Dockerhub page does not mention armv32v6
as supported. It is possible this may have been dropped
because builds passed previously, but as of today running
echo in a Ubuntu base image on a RaspberryPi fails.

We also notice the following error when issuing a build
on the RPI with the Ubuntu base image:

    [Warning] The requested image's platform (linux/arm/v7)
    does not match the detected host platform (linux/arm/v6)
    and no specific platform was requested

Change-type: patch
Signed-off-by: Alexandru Costache <[email protected]>

Author: acostach

module/Dockerfile.template

@@ -1,17 +1,17 @@
-FROM ubuntu:jammy-20220531 as kernel-build
+FROM alpine:20251224 as kernel-build
 
 ARG DEBIAN_FRONTEND=noninteractive
 ENV TZ=Etc/UTC
 
-RUN apt-get update && \
-    apt-get install -y \
+RUN apk add --no-cache \
     bison \
-    build-essential \
+    build-base \
     flex \
-    libelf-dev \
-    libssl-dev \
+    elfutils-dev \
+    openssl-dev \
     bc \
-    wget
+    wget \
+    bash
 
 WORKDIR /usr/src/app