split metrics installer image

docker/ours-rp-runtime.Dockerfile

@@ -84,14 +84,12 @@ RUN --mount=type=cache,target=/usr/local/cargo/registry \
     cargo build --release --target "$target_triple" \
       --bin rpki \
       --bin rpki_daemon \
-      --bin db_stats \
-      --bin rpki_artifact_metrics; \
+      --bin db_stats; \
     mkdir -p /build-out/bin; \
     cp \
       "target/$target_triple/release/rpki" \
       "target/$target_triple/release/rpki_daemon" \
       "target/$target_triple/release/db_stats" \
-      "target/$target_triple/release/rpki_artifact_metrics" \
       /build-out/bin/
 
 FROM --platform=$TARGETPLATFORM ${RUNTIME_IMAGE} AS runtime