Removed some variants to reduce build time.

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightStandard.shader

             #pragma shader_feature _SPECULAR_SETUP
 
             #pragma multi_compile _ _MAIN_LIGHT_COOKIE
-            #pragma multi_compile _MAIN_DIRECTIONAL_LIGHT _MAIN_SPOT_LIGHT _MAIN_POINT_LIGHT
+            #pragma multi_compile _MAIN_DIRECTIONAL_LIGHT _MAIN_SPOT_LIGHT
-            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE _MIXED_LIGHTING_SHADOWMASK
+            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE
             #pragma multi_compile _ UNITY_SINGLE_PASS_STEREO STEREO_INSTANCING_ON STEREO_MULTIVIEW_ON
             #pragma multi_compile _ LIGHTMAP_ON
             #pragma multi_compile _ DIRLIGHTMAP_COMBINED

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightStandardSimpleLighting.shader

             #pragma multi_compile _ _MAIN_LIGHT_COOKIE
             #pragma multi_compile _MAIN_DIRECTIONAL_LIGHT _MAIN_SPOT_LIGHT
             #pragma multi_compile _ _ADDITIONAL_LIGHTS
-            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE _MIXED_LIGHTING_SHADOWMASK
+            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE
             #pragma multi_compile _ UNITY_SINGLE_PASS_STEREO STEREO_INSTANCING_ON STEREO_MULTIVIEW_ON
             #pragma multi_compile _ LIGHTMAP_ON
             #pragma multi_compile _ DIRLIGHTMAP_COMBINED

ScriptableRenderPipeline/LightweightPipeline/Shaders/LightweightStandardTerrain.shader

             #include "LightweightLighting.cginc"
 
             #pragma multi_compile _ _MAIN_LIGHT_COOKIE
-            #pragma multi_compile _MAIN_DIRECTIONAL_LIGHT _MAIN_SPOT_LIGHT _MAIN_POINT_LIGHT
+            #pragma multi_compile _MAIN_DIRECTIONAL_LIGHT _MAIN_SPOT_LIGHT
-            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE _MIXED_LIGHTING_SHADOWMASK
+            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE
             #pragma multi_compile _ UNITY_SINGLE_PASS_STEREO STEREO_INSTANCING_ON STEREO_MULTIVIEW_ON
             #pragma multi_compile _ LIGHTMAP_ON
             #pragma multi_compile _ DIRLIGHTMAP_COMBINED