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

* move grafana-build into pkg/build

pkg/build/daggerbuild/frontend/node.go

@@ -0,0 +1,32 @@
+package frontend
+
+import (
+	"fmt"
+	"strings"
+
+	"dagger.io/dagger"
+)
+
+// NodeVersionContainer returns a container whose `stdout` will return the node version from the '.nvmrc' file in the directory 'src'.
+func NodeVersion(d *dagger.Client, src *dagger.Directory) *dagger.Container {
+	return d.Container().From("alpine:3.17").
+		WithMountedDirectory("/src", src).
+		WithWorkdir("/src").
+		WithExec([]string{"cat", ".nvmrc"})
+}
+
+func NodeImage(version string) string {
+	return fmt.Sprintf("node:%s-slim", strings.TrimPrefix(strings.TrimSpace(version), "v"))
+}
+
+// NodeContainer returns a docker container with everything set up that is needed to build or run frontend tests.
+func NodeContainer(d *dagger.Client, base string, platform dagger.Platform) *dagger.Container {
+	container := d.Container(dagger.ContainerOpts{
+		Platform: platform,
+	}).From(base).
+		WithExec([]string{"apt-get", "update", "-yq"}).
+		WithExec([]string{"apt-get", "install", "-yq", "make", "git", "g++", "python3"}).
+		WithEnvVariable("NODE_OPTIONS", "--max_old_space_size=8000")
+
+	return container
+}