fix use copy to ensure cache

7 jobs for gitlabci in 3 minutes and 17 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Prepare
passed #11257
linux
mat_irrklang

00:00:42

passed #11258
linux
mat_linux

00:00:39

passed #11256
linux
mat_lua

00:00:32

passed #11259
linux
mat_mac

00:00:35

passed #11260
linux
mat_windows

00:00:40

 
  Build
passed #11262
linux
linux_exec

00:02:14

passed #11261
vs
windows_exec

00:02:33