Update Magefile to only build 4 platform,not LinuxARM. Close #10

Author: jovezhong

Magefile.go

@@ -6,7 +6,13 @@ package main
 import (
 	// mage:import
 	build "github.com/grafana/grafana-plugin-sdk-go/build"
+	"github.com/magefile/mage/mg"
 )
 
+func Build4() { //revive:disable-line
+	b := build.Build{}
+	mg.Deps(b.Windows, b.Darwin, b.DarwinARM64, b.LinuxARM64, b.GenerateManifestFile)
+}
+
 // Default configures the default target.
-var Default = build.BuildAll
+var Default = Build4