Only include dri.h with older versions of xserver

Not needed anymore with current versions.
12 jobs for drop-dri-h-includes in 1 minute and 5 seconds (queued for 1 second)
Status Job ID Name Coverage
  Docker Image
passed container-build #9619718

00:00:11

 
  Build
passed build-clang: [1.18] #9619725

00:00:39

passed build-clang: [1.19] #9619726

00:00:39

passed build-clang: [1.20] #9619724

00:00:42

passed build-distcheck #9619719

00:00:54

passed build-gcc: [1.16] #9619720

00:00:44

passed build-gcc: [1.17] #9619721

00:00:44

passed build-gcc: [1.18] #9619722

00:00:43

passed build-gcc: [1.19] #9619723

00:00:43

passed build-noglamor: [1.13] #9619727

00:00:39

passed build-noglamor: [1.14] #9619728

00:00:34

passed build-noglamor: [1.15] #9619729

00:00:39