build(container): use alpine:3 instead of specific 3.17

The version was pinned for GitHub runner cache to be faster to download.
The action no longer uses the docker version here so the benefit is
smaller and requires more maintenance to update on updates.
Its unlikely to break as mainly git and the precompiled binary are used.

Dockerfile

@@ -20,8 +20,7 @@ RUN strip target/release/website-stalker
 
 
 # Start building the final image
-# Use one of the cached base images https://github.com/actions/runner-images/blob/main/images/linux/Ubuntu2004-Readme.md#cached-docker-images
-FROM docker.io/library/alpine:3.17
+FROM docker.io/library/alpine:3
 RUN apk upgrade --no-cache \
 	&& apk add --no-cache git