chore(e2e): Stop running current builds with new pushes (#6309)

Added a concurrency check in the github workflow to stop running build action if new changes are pushed.

.github/workflows/build.yml

@@ -11,6 +11,10 @@ on:
   workflow_call:
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 env:
   PKG_NAME: "boundary"