[Flow202][electron-update-server][skip-ci] [2/3] Use the same flow-typed libdef for express throughout our codebase
Summary:
The electron-update-server one has some newer changes from upstream, but the keyserver one has our sameSite change.
NOTE: CI will fail on this diff. I considered the possibility of fixing Flow errors BEFORE upgrading Flow, but it wasn't possible... in some cases, the fixes to support the new version o
f Flow caused errors in the old version. I could have hidden these type errors with $FlowFixMe lines and then later revert those, but that seemed like too much busy work.
Depends on D9716
Test Plan: Make sure no additional Flow error introduced on keyserver or electron-update-server
Reviewers: michal, jon
Reviewed By: michal
Subscribers: tomek, wyilio
Differential Revision: https://phab.comm.dev/D9717