MFH: r531390

graphics/libavif: fix build on GCC architectures

Use newer GCC to avoid error caused by -Werror:
/wrkdirs/usr/ports/graphics/libavif/work/libavif-0.6.3/src/reformat.c:316: warning: comparison is always false due to limited range of data type

Approved by: portmgr (fix build blanket)