modified Dockerfile source images to use smaller base images

Dockerfile

@@ -1,7 +1,7 @@
 # We use the latest Go 1.x version unless asked to use something else.
 # The GitHub Actions CI job sets this argument for a consistent Go version.
 ARG GO_VERSION=1
-ARG BASE_IMAGE=kcllang/kcl
+ARG BASE_IMAGE=debian:bookworm-slim
 
 # Setup the base environment. The BUILDPLATFORM is set automatically by Docker.
 # The --platform=${BUILDPLATFORM} flag tells Docker to build the function using
@@ -33,7 +33,7 @@ ARG TARGETARCH
 RUN --mount=target=. \
     --mount=type=cache,target=/go/pkg/mod \
     --mount=type=cache,target=/root/.cache/go-build \
-    GOOS=${TARGETOS} GOARCH=${TARGETARCH} go build -o /function .
+    GOOS=${TARGETOS} GOARCH=${TARGETARCH} go build -ldflags "-w -s" -o /function .
 
 # Produce the Function image. We use a very lightweight 'distroless' image that
 # does not include any of the build tools used in previous stages.