fuzz: Remove expensive and redundant muhash from crypto fuzz target

src/test/fuzz/muhash.cpp

@@ -41,6 +41,11 @@ FUZZ_TARGET(muhash)
     muhash.Finalize(out2);
 
     assert(out == out2);
+    MuHash3072 muhash3;
+    muhash3 *= muhash;
+    uint256 out3;
+    muhash3.Finalize(out3);
+    assert(out == out3);
 
     // Test that removing all added elements brings the object back to it's initial state
     muhash /= muhash;
@@ -50,4 +55,9 @@ FUZZ_TARGET(muhash)
     muhash2.Finalize(out2);
 
     assert(out == out2);
+
+    muhash3.Remove(data);
+    muhash3.Remove(data2);
+    muhash3.Finalize(out3);
+    assert(out == out3);
 }