chore(workflow): add workflow_dispatch in build.yml

Longhorn 10701

Signed-off-by: Derek Su <[email protected]>

Author: derekbit

.github/workflows/build.yml

@@ -7,6 +7,9 @@ on:
     tags:
     - v*
   pull_request:
+
+  workflow_dispatch:
+
 jobs:
   build:
     name: Build binaries