devel/microsoft-gsl: Upstream rerolled release/distfile

Upstream rerolled release/distfile as previous still had versioning
referring to previous version

Previous commit backports upstream commit
f8ec3091183e44b53a36b8f3857f234767f8ed8a which fixes a performance
issue with span_iterator when compiled using LLVM/Clang

Reference:
https://github.com/microsoft/GSL/commit/f8ec3091183e44b53a36b8f3857f234767f8ed8a

Reported by: cmt
Approved by: portmgr (blanket, build fix)