Removed #extension directives which are meant only for GLSL and which caused compiler warnings in Unity

Assets/Resources/FSR2/shaders/ffx_spd.h

@@ -91,9 +91,6 @@ FfxFloat32x4 SpdReduce4(FfxFloat32x4 v0, FfxFloat32x4 v1, FfxFloat32x4 v2, FfxFl
 #endif // #ifdef SPD_PACKED_ONLY
 
 //_____________________________________________________________/\_______________________________________________________________
-#if defined(FFX_GLSL) && !defined(SPD_NO_WAVE_OPERATIONS)
-#extension GL_KHR_shader_subgroup_quad:require
-#endif
 
 void SpdWorkgroupShuffleBarrier()
 {
@@ -529,10 +526,6 @@ void SpdDownsample(FfxUInt32x2 workGroupID, FfxUInt32 localInvocationIndex, FfxU
 
 #if FFX_HALF
 
-#ifdef FFX_GLSL
-#extension GL_EXT_shader_subgroup_extended_types_float16:require
-#endif
-
 FfxFloat16x4 SpdReduceQuadH(FfxFloat16x4 v)
 {
 #if defined(FFX_GLSL) && !defined(SPD_NO_WAVE_OPERATIONS)