CI: move grafana-build into pkg/build (#105640)

* move grafana-build into pkg/build

.github/workflows/pr-e2e-tests.yml

@@ -22,20 +22,14 @@ jobs:
     outputs:
       artifact: ${{ steps.artifact.outputs.artifact }}
     steps:
-      - uses: actions/checkout@v4
-        with:
-          repository: 'grafana/grafana-build'
-          ref: 'main'
-          persist-credentials: false
       - uses: actions/checkout@v4
         with:
           path: ./grafana
           persist-credentials: false
-      - run: echo "GRAFANA_GO_VERSION=$(grep "go 1." grafana/go.work |  cut -d\  -f2)" >> "$GITHUB_ENV"
       - uses: dagger/dagger-for-github@e47aba410ef9bb9ed81a4d2a97df31061e5e842e
         with:
           verb: run
-          args: go run ./cmd artifacts -a targz:grafana:linux/amd64 --grafana-dir=grafana --go-version=${GRAFANA_GO_VERSION} > out.txt
+          args: go -C grafana run ./pkg/build/cmd artifacts -a targz:grafana:linux/amd64 --grafana-dir="${PWD}/grafana" > out.txt
       - run: mv "$(cat out.txt)" grafana.tar.gz
       - run: echo "artifact=grafana-e2e-${{github.run_number}}" >> "$GITHUB_OUTPUT"
         id: artifact