Allowing null values to be set for SelectedDrynessLevel  (#31522)

* Allowing null values to be set for SelectedDrynessLevel in LaundryDryerControls

* Restyled by clang-format

---------

Co-authored-by: Restyled.io <commits@restyled.io>
diff --git a/src/app/clusters/laundry-dryer-controls-server/laundry-dryer-controls-server.cpp b/src/app/clusters/laundry-dryer-controls-server/laundry-dryer-controls-server.cpp
index 32adbef..3c3bc52 100644
--- a/src/app/clusters/laundry-dryer-controls-server/laundry-dryer-controls-server.cpp
+++ b/src/app/clusters/laundry-dryer-controls-server/laundry-dryer-controls-server.cpp
@@ -163,6 +163,10 @@
     {
     case Attributes::SelectedDrynessLevel::Id: {
         uint8_t drynessLevelIdx = 0;
+        if (NumericAttributeTraits<uint8_t>::IsNullValue(*value))
+        {
+            return Status::Success;
+        }
         while (true)
         {
             DrynessLevelEnum supportedDryness;