Fix production builds for Flask (#16757)

.circleci/config.yml

@@ -344,9 +344,25 @@ jobs:
       - checkout
       - attach_workspace:
           at: .
+      - when:
+          condition:
+            not:
+              matches:
+                pattern: /^master$/
+                value: << pipeline.git.branch >>
+          steps:
             - run:
                 name: build:dist
                 command: yarn build --build-type flask dist
+      - when:
+          condition:
+              matches:
+                pattern: /^master$/
+                value: << pipeline.git.branch >>
+          steps:
+            - run:
+                name: build:prod
+                command: yarn build --build-type flask prod
       - run:
           name: build:debug
           command: find dist/ -type f -exec md5sum {} \; | sort -k 2