Find bug on checking architecture

Hi.
I found bug at Twain#getArch().

On Windows11, System.getProperty("os.name") returns "Windows11" and getArch() returns "32",
32bit JRE on Windows10 64bit returns "64".
Why dont you use Native.POINTER_SIZE to check architecture.

e.g.
`return (Native.POINTER_SIZE == 8) ? "64" : "32";
`

Thank you for the wonderful program 😄 