Allow overriding the meta-balena ref for workflow dispatch

This enables manual testing of meta-balena PRs directly
on device repos.

Changelog-entry: Allow custom meta-balena ref on workflow dispatch
Signed-off-by: Florin Sarbu <florin@balena.io>

.github/workflows/owa5x.yml

@@ -30,6 +30,11 @@ on:
         required: false
         type: string
         default: balena-staging.com
+      meta-balena-ref:
+        description: meta-balena ref if not the currently pinned version
+        required: false
+        type: string
+        default: ''
 
 jobs:
   yocto:
@@ -47,3 +52,5 @@ jobs:
       force-finalize: ${{ inputs.force-finalize || false }}
       # Default to balena-staging.com for workflow dispatch, but balena-cloud.com for other events
       deploy-environment: ${{ inputs.deploy-environment || 'balena-cloud.com' }}
+      # Allow overriding the meta-balena ref for workflow dispatch events
+      meta-balena-ref: ${{ inputs.meta-balena-ref || '' }}