sysutils/edk2: Depend on GCC at build time only

EDK2 produces self-contained binary runtime data which do not require GCC at
runtime, but only at build time.

Reviewed by: fuz
MFH: 2026Q2
Differential Revision: https://reviews.freebsd.org/D57187

(cherry picked from commit 64e6ea052e3a1b183f83867e303b289fe1eb88e1)