Upgrade klayout to 0.25.4
Summary:
klayout 0.25.4 was released. It requires a patch to compile.
Changelog: https://www.klayout.de/development.html
Test Plan: Open a few GDS files (kB to GB in size) and browse the layout.
Reviewers: Triage Team, sunnyflunk
Reviewed By: Triage Team, sunnyflunk
Subscribers: sunnyflunk
Differential Revision: https://dev.getsol.us/D3841