fix image variant in tests

Author: julienp

.github/workflows/ci.yml

@@ -152,7 +152,7 @@ jobs:
           chmod o+r $GOOGLE_APPLICATION_CREDENTIALS
           docker run \
             -e RUN_CONTAINER_TESTS=true \
-            -e IMAGE_VARIANT=pulumi \
+            -e IMAGE_VARIANT=pulumi${{ matrix.variant }} \
             -e PULUMI_ACCESS_TOKEN=${PULUMI_ACCESS_TOKEN} \
             -e PULUMI_ORG=${PULUMI_ORG} \
             -e ARM_CLIENT_ID=${ARM_CLIENT_ID} \