Fix OverridableReleaseSpec

Author: MarekM25

src/Nethermind/Nethermind.Specs.Test/OverridableReleaseSpec.cs

@@ -155,8 +155,30 @@ public ulong Eip4844TransitionTimestamp
             }
         }
 
-        public ulong TargetBlobCount => _spec.TargetBlobCount;
-        public ulong MaxBlobCount => _spec.MaxBlobCount;
+        private ulong? _overridenTargetBlobCount;
+        public ulong TargetBlobCount
+        {
+            get
+            {
+                return _overridenTargetBlobCount ?? _spec.TargetBlobCount;
+            }
+            set
+            {
+                _overridenTargetBlobCount = value;
+            }
+        }
+        private ulong? _overridenMaxBlobCount;
+        public ulong MaxBlobCount
+        {
+            get
+            {
+                return _overridenMaxBlobCount ?? _spec.MaxBlobCount;
+            }
+            set
+            {
+                _overridenMaxBlobCount = value;
+            }
+        }
         public bool IsEip1153Enabled => _spec.IsEip1153Enabled;
         public bool IsEip3651Enabled => _spec.IsEip3651Enabled;
         public bool IsEip3855Enabled => _spec.IsEip3855Enabled;