Fix shadow algorithm reserve size

com.unity.render-pipelines.core/CoreRP/Shadow/Shadow.cs

         override protected void Register(GPUShadowType type, ShadowRegistry registry)
         {
             ShadowPrecision precision = m_ShadowmapBits == 32 ? ShadowPrecision.High : ShadowPrecision.Low;
-            m_SupportedAlgorithms.Reserve(5);
+            m_SupportedAlgorithms.Reserve(6);
             m_SupportedAlgorithms.AddUniqueUnchecked((int)ShadowUtils.Pack(ShadowAlgorithm.PCF, ShadowVariant.V0, precision));
             m_SupportedAlgorithms.AddUniqueUnchecked((int)ShadowUtils.Pack(ShadowAlgorithm.PCF, ShadowVariant.V1, precision));
             m_SupportedAlgorithms.AddUniqueUnchecked((int)ShadowUtils.Pack(ShadowAlgorithm.PCF, ShadowVariant.V2, precision));