[Key Vault] Update tests.yml for test proxy (Azure#23786)

Author: mccoyp

sdk/keyvault/tests.yml

@@ -37,6 +37,7 @@ stages:
               GenerateVMJobs: true
         EnvVars:
           AZURE_TEST_RUN_LIVE: true
+          AZURE_SKIP_LIVE_RECORDING: 'True'
           AZURE_SUBSCRIPTION_ID: $(azure-subscription-id)
           AZURE_TENANT_ID: $(aad-azure-sdk-test-tenant-id)
           AZURE_CLIENT_ID: $(aad-azure-sdk-test-client-id)