Revert "remove --frozen-lockfile option"

This reverts commit 5130329fe852b0f98a47d2a0314b1d22ce7c4902.

apps/app/docker/Dockerfile

@@ -34,7 +34,7 @@ COPY --from=base ${optDir}/out/yarn.lock ./yarn.lock
 
 # setup (with network-timeout = 1 hour)
 RUN yarn config set network-timeout 3600000
-RUN yarn
+RUN yarn --frozen-lockfile
 
 # make artifacts
 RUN tar -cf node_modules.tar \

apps/slackbot-proxy/docker/Dockerfile

@@ -29,7 +29,7 @@ COPY --from=base ${optDir}/out/yarn.lock ./yarn.lock
 
 # setup (with network-timeout = 1 hour)
 RUN yarn config set network-timeout 3600000
-RUN yarn
+RUN yarn --frozen-lockfile
 
 # make artifacts
 RUN tar -cf node_modules.tar \