Fix path for tier 3 template in the nightly build (#703)

Co-authored-by: Bree Stryker <b-s-no-reply@microsoft.com>

.azure-devops/nightlybuild/templates/az-deployment.yml

@@ -54,5 +54,5 @@ steps:
            --subscription ${{ parameters.WorkloadSubId }} \
            --location ${{ parameters.Location }} \
            --name ${{ parameters.WorkloadName }} \
-           --template-file $(Build.SourcesDirectory)/src/bicep/examples/tier3/tier3.bicep \
+           --template-file $(Build.SourcesDirectory)/src/bicep/add-ons/tier3/tier3.bicep \
            --parameters resourcePrefix=$datetime