Turn off 2022 fundraising announcements for now.

This makes the announcement return an empty array, but leaves the
rest of the logic in place, in case we want to enable the announcements.

I didn't want to fully revert the original patch, since it removed
unnecessary logic that we didn't need anyway.

Change-Id: Idc2ccbfd9cd192e75e7769031df3062c7c3262c4