Copy cue.mod and packages/grafana-schema to container workdir (#38998) (#39018)

(cherry picked from commit 78b3847014)

Co-authored-by: Dimitris Sotirakis <dimitrios.sotirakis@grafana.com>

Dockerfile

@@ -25,6 +25,8 @@ WORKDIR $GOPATH/src/github.com/grafana/grafana
 
 COPY go.mod go.sum embed.go ./
 COPY cue cue
+COPY cue.mod cue.mod
+COPY packages/grafana-schema packages/grafana-schema
 COPY public/app/plugins public/app/plugins
 COPY pkg pkg
 COPY build.go package.json ./

Dockerfile.ubuntu

@@ -25,6 +25,8 @@ COPY go.mod go.sum embed.go ./
 COPY build.go package.json ./
 COPY pkg pkg/
 COPY cue cue/
+COPY cue.mod cue.mod/
+COPY packages/grafana-schema packages/grafana-schema/
 COPY public/app/plugins public/app/plugins/
 
 RUN go mod verify