A big portion of the code generation uses templates. Since you're using VB the templates can be found in your Visual Studio folder, e.g.
C:\Program Files\Microsoft Visual Studio\2022\Community\VB\Snippets\1033\common code patterns\types
As you can see the actual path depends on the version you're using but it should be easy to locate. Just look for the template named
ImplementTheDisposeFinalizePattern.snippet
You can use basically any text editor to see and modify the content of the snippet