Remove the support for older dynamic jekyll workflows

The pages dynamic workflow now decouples telemetry from deploy for 100%
of users, so we can remove this old conditional.

action.yml

@@ -7,6 +7,7 @@ inputs:
   emit_telemetry:
     description: 'Should this action only emit build telemetry instead of deploying the build artifact?'
     required: false
+    default: "false"
   token:
     description: 'GitHub token'
     default: ${{ github.token }}