fixup dev dockerfile

Dockerfile

@@ -5,11 +5,6 @@
 
 ARG RUST_IMAGE=ghcr.io/linkerd/dev:v42-rust
 
-# Use an arbitrary ~recent edge release image to get the proxy
-# identity-initializing and linkerd-await wrappers.
-# Currently pinned to a build off of edge-23.11.1 + dev:v42
-ARG RUNTIME_IMAGE=ghcr.io/olix0r/l2-proxy:git-04283611
-
 # Build the proxy.
 FROM --platform=$BUILDPLATFORM $RUST_IMAGE as build
 
@@ -39,9 +34,18 @@ RUN --mount=type=cache,id=cargo,target=/usr/local/cargo/registry \
     mkdir -p /out && \
     mv $(just --evaluate profile="$PROFILE" _target_bin) /out/linkerd2-proxy
 
-## Install the proxy binary into the base runtime image.
-FROM $RUNTIME_IMAGE as runtime
+# Use an arbitrary ~recent edge release image to get the proxy
+# identity-initializing and linkerd-await wrappers.
+# Currently pinned to a build off of edge-23.11.1 + dev:v42
+ARG LINKERD2_IMAGE=ghcr.io/olix0r/l2-proxy:git-04283611
+FROM $LINKERD2_IMAGE as linkerd2
+
+# Install the proxy binary into a base image that we can at least get a shell to
+# debug on.
+FROM docker.io/library/debian:bookworm-slim as runtime
 WORKDIR /linkerd
+COPY --from=linkerd2 /usr/lib/linkerd/linkerd-await /usr/lib/linkerd/linkerd-await
+COPY --from=linkerd2 /usr/lib/linkerd/linkerd2-network-validator /usr/lib/linkerd/linkerd2-network-validator
+COPY --from=linkerd2 /usr/lib/linkerd/linkerd2-proxy-identity /usr/lib/linkerd/linkerd2-proxy-identity
 COPY --from=build /out/linkerd2-proxy /usr/lib/linkerd/linkerd2-proxy
-ENV LINKERD2_PROXY_LOG=warn,linkerd=info,trust_dns=error
-# Inherits the ENTRYPOINT from the runtime image.
+ENTRYPOINT ["/usr/lib/linkerd/linkerd2-proxy-identity"]