Remove redundant nullable annotation (#113550)

The nullable annotation on type constraint 'IEquatable<T>?' is redundant because type parameter 'T' has 'struct' constraint.

Co-authored-by: Aaron Robinson <[email protected]>
Co-authored-by: Eirik Tsarpalis <[email protected]>

Author: 3 people

src/libraries/System.Private.CoreLib/src/System/SpanHelpers.T.cs

@@ -3794,7 +3794,7 @@ public static int Count<T>(ref T current, T value, int length) where T : IEquata
             return count;
         }
 
-        public static unsafe int CountValueType<T>(ref T current, T value, int length) where T : struct, IEquatable<T>?
+        public static unsafe int CountValueType<T>(ref T current, T value, int length) where T : struct, IEquatable<T>
         {
             int count = 0;
             ref T end = ref Unsafe.Add(ref current, length);