Update libgdiplus to 6.0.2
Summary: No changelog provided by upstream.
Test Plan: Random .NET Application works (Steam Desktop Authenticator); Keepass works too.
Reviewers: Triage Team, JoshStrobl
Reviewed By: Triage Team, JoshStrobl
Subscribers: JoshStrobl
Differential Revision: https://dev.getsol.us/D7134