fix: remove UI from docker build (#19425)

Author: fcjack

cmd/loki/Dockerfile

@@ -1,17 +1,9 @@
 ARG GO_VERSION=1.24
 
-# UI build stage
-FROM node:22-alpine AS ui-builder
-RUN apk add --no-cache make
-COPY . /src/loki
-WORKDIR /src/loki
-RUN make -C pkg/ui/frontend build
-
 # Go build stage
 FROM golang:${GO_VERSION} AS build
 ARG IMAGE_TAG
 COPY . /src/loki
-COPY --from=ui-builder /src/loki/pkg/ui/frontend/dist /src/loki/pkg/ui/frontend/dist
 WORKDIR /src/loki
 RUN make clean && make BUILD_IN_CONTAINER=false IMAGE_TAG=${IMAGE_TAG} loki