Fixed broken cascade selection with high camera FoVs.

Assets/ScriptableRenderPipeline/ShaderLibrary/Shadow/ShadowAlgorithms.hlsl

 	dirShadowSplitSphereSqRadii.z = dirShadowSplitSpheres[2].w;
 	dirShadowSplitSphereSqRadii.w = dirShadowSplitSpheres[3].w;
 
-	if( distances2.w > dirShadowSplitSphereSqRadii.w )
-		return -1;
-
-	return int( 4.0 - dot( weights, float4(4.0, 3.0, 2.0, 1.0 ) ) );
+	int idx = int( 4.0 - dot( weights, float4( 4.0, 3.0, 2.0, 1.0 ) ) );
+	return idx <= 3 ? idx : -1;
 }
 
 uint EvalShadow_LoadSplitSpheres( ShadowContext shadowContext, int index, out float4 splitSpheres[4] )