ci: Store production built assets to /tmp/production-build.

Previously, we copied them to /tmp and from there we specified those
assets we copied in circleci config in presist_to_workspace step.
Copying it to a directory allows us to get rid of list in circleci
config and GitHub Actions's upload artifact (their version of
presist to workspace) doesn't allow us to specify indivivual files
so only is this cleaner but required.

.circleci/config.yml

@@ -294,16 +294,10 @@ jobs:
           # or relative path from working_directory.
           # This is a directory on the container which is
           # taken to be the root directory of the workspace.
-          root: /tmp
+          root: /tmp/production-build
           # Must be relative path from root
           paths:
-            - zulip-server-test.tar.gz
-            - success-http-headers.template.txt
-            - production-install
-            - production-verify
-            - production-upgrade-pg
-            - production
-            - production-extract-tarball
+            - "*"
       - *notify_failure_status
 
   "bionic-production-install":

tools/ci/production-build

@@ -28,14 +28,15 @@ if ! ./tools/build-release-tarball test; then
     exit 1
 fi
 
-# This list matches up against the persist_to_workspace step in
-# .circleci/config.yml
-mv /tmp/tmp.*/zulip-server-test.tar.gz /tmp/
+# Move all the required artifacts to /tmp/production-build
+# that will be later sent down to downstream install jobs.
+mkdir /tmp/production-build
+mv /tmp/tmp.*/zulip-server-test.tar.gz /tmp/production-build
 cp -a \
    tools/ci/success-http-headers.template.txt \
    tools/ci/production-install \
    tools/ci/production-verify \
    tools/ci/production-upgrade-pg \
    tools/ci/production-extract-tarball \
    \
-   /tmp/
+   /tmp/production-build