Blender Git Loki

GPU: Remove local shaders workaround for Intel/Windows

It has been tested that local shaders workaround isn't needed for the
latest Windows/Intel 6xx GPU's.

Currently the local shaders workaround doesn't work anymore during the
investigation it was detected that the intel drivers didn't need it
anymore.

Local shaders should still be fixed as it is also used for some legacy
iGPU's. The current work around crashes when doing preview renders in
EEVEE as the default materials aren't available but for the work around
they should. (See T77346 for more information)