Add LICENSE file to generated Docker images (#74082)

Dockerfile

@@ -64,6 +64,7 @@ COPY pkg pkg
 COPY scripts scripts
 COPY conf conf
 COPY .github .github
+COPY LICENSE ./
 
 ENV COMMIT_SHA=${COMMIT_SHA}
 ENV BUILD_BRANCH=${BUILD_BRANCH}
@@ -165,6 +166,7 @@ RUN if [ ! $(getent group "$GF_GID") ]; then \
 
 COPY --from=go-src /tmp/grafana/bin/grafana* /tmp/grafana/bin/*/grafana* ./bin/
 COPY --from=js-src /tmp/grafana/public ./public
+COPY --from=go-src /tmp/grafana/LICENSE ./
 
 EXPOSE 3000