build with buildkit on CI

Author: minrk

.circleci/config.yml

@@ -52,6 +52,7 @@ jobs:
 
       - run:
           command: |
+            export DOCKER_BUILDKIT=1
             chartpress
           name: Run chartpress
 

.github/workflows/test-chart.yaml

@@ -247,6 +247,8 @@ jobs:
         run: |
           pip3 install -r dev-requirements.txt
           chartpress
+        env:
+          DOCKER_BUILDKIT: "1"
 
       # Generate values.schema.json from schema.yaml
       - name: Generate values.schema.json from schema.yaml