Fix Typescript deprecation

[amanteaux]

Since Typescript 4.8, usage of createGetAccessorDeclaration and updateClassDeclaration has been deprecated. It needs to be replaced.

Currently, running the transformer with TS >= 4.8 generate these warnings:

DeprecationWarning: 'createGetAccessorDeclaration' has been deprecated since v4.8.0. Decorators have been combined with modifiers. Callers should switch to an overload that does not accept a
 'decorators' parameter.
DeprecationWarning: 'updateClassDeclaration' has been deprecated since v4.8.0. Decorators have been combined with modifiers. Callers should switch to an overload that does not accept a 'deco
rators' parameter.