Rugerize waf encoder disposal

Author: daniel-romano-DD

tracer/src/Datadog.Trace/AppSec/Security.cs

@@ -487,7 +487,7 @@ private string GetHtmlResponse()
         public void Dispose()
         {
             _waf?.Dispose();
-            Encoder.Pool.Dispose();
+            Encoder.Dispose();
             _activeAddressesLocker.Dispose();
         }
 

tracer/src/Datadog.Trace/AppSec/WafEncoding/Encoder.cs

@@ -47,6 +47,22 @@ internal static UnmanagedMemoryPool Pool
             }
         }
 
+        internal static void Dispose()
+        {
+            try
+            {
+                if (_pool is { IsDisposed: false })
+                {
+                    _pool.Dispose();
+                    _pool = null;
+                }
+            }
+            catch (Exception ex)
+            {
+                Log.Debug(ex, "WafEncoder Crashed on shutdown.");
+            }
+        }
+
         /// <summary>
         /// For testing purposes
         /// </summary>