fix time.Time fields not being saved

via adding a special case in the `serializeIDs` function (in document_internals.go)

document_internals.go

@@ -84,7 +84,11 @@ func serializeIDs(input interface{}) interface{} {
 					}
 
 				} else {
-					ret0[bbson.Name] = serializeIDs(fv.Interface())
+					if fv.Type() == reflect.TypeFor[time.Time]() {
+						ret0[bbson.Name] = fv.Interface()
+					} else {
+						ret0[bbson.Name] = serializeIDs(fv.Interface())
+					}
 				}
 			}