Revert "Add VecCore as external project"
Revert "Add VecCore as external project"

This reverts commit 5d3a1150015057bcdb7bb90481fea78782857647.

zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root-compressor-dummy