Add "?" to nullable parameters in functions

[MatthiasKuehneEllerhold]

Using the lib in a php 8.4 project leads to this error:

PHP Deprecated:  Icewind\SMB\Native\NativeState::lseek(): Implicitly marking parameter $path as nullable is deprecated, the explicit nullable type must be used instead in /.../vendor/icewind/smb/src/Native/NativeState.php on line 346

I found two parameters that have a default value of null but arent nullable.

[MatthiasKuehneEllerhold]

The first CI run failed because the ubuntu-20.04 runner was removed by github two weeks ago. I upgraded to 22.04. Please advice if this is correct.