ci: enable workflow_dispatch (#137)

The commit enables the `workflow_dispatch` so we can manually trigger CI
when needed.

Signed-off-by: vince-fugnitto <[email protected]>

Author: vince-fugnitto

.github/workflows/ci-cd.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - master
+  workflow_dispatch:
   pull_request:
     branches:
       - master