CMake: update dependencies to latest release

CMake: RTTS - drop separation between core and ext shaders

Samples: fix depth shadow caster for HLSL4

GL3+: support loading SPIRV shaders

CI: build 1.12.1 SDK packages

RTSS: slightly simplify Lighting parameter resolution

CMake: Bites - issue a warning if SDL2 was not found

D3D9: we must use TU_DYNAMIC for mipmap generation on D3D9Ex

GLSupport: remove dependency on legacy libGL.so

Terrain: really reduce requirements to GLSL120

fixes "flat" terrain on GL rendersystem with drivers only exposing 3.0
compatibility profile, hence GLSL130