Switch to alpine

Dockerfile

@@ -1,5 +1,5 @@
 # Use the official Caddy builder
-FROM caddy:builder AS builder
+FROM caddy:builder-alpine AS builder
 
 # Build Caddy with the Layer 4 module included
 RUN xcaddy build \
@@ -7,5 +7,5 @@ RUN xcaddy build \
     --with github.com/caddyserver/jsonc-adapter
 
 # Pull the compiled binary into the final lightweight image
-FROM caddy:latest
+FROM caddy:alpine
 COPY --from=builder /usr/bin/caddy /usr/bin/caddy