Add workflow_dispatch to github workflow.

[git-p4: depot-paths = "//dev/release.net/coherence-net-v14.1.1.0/": change = 106705]

Author: chpatel3

.github/workflows/build.yml

@@ -9,6 +9,7 @@
 name: CI Build
 
 on:
+  workflow_dispatch:
   push:
     branches-ignore:
     - gh-pages