swig --version doesn't work in all versions of swig; -version should be used instead

Did code inspection and it looks like `setup.py` relies on `swig --version` returning something meaningful (see the linked code below).

`--version` isn't implemented on all versions of swig (it seems that it's only technically implemented on the MacOS version of the package).

### FreeBSD
```
% swig --version
Unable to find option or file '--version', Use 'swig -help' for more information.
% swig -version 

SWIG Version 4.2.1

Compiled with c++ [amd64-portbld-freebsd14.3]

Configured options: +pcre

Please see https://www.swig.org for reporting bugs and further information
```

### Linux
```
% lsb_release -a
No LSB modules are available.
Distributor ID: Raspbian
Description:    Raspbian GNU/Linux 12 (bookworm)
Release:        12
Codename:       bookworm
% swig --version
Unable to find option or file '--version', Use 'swig -help' for more information.
% swig -version 

SWIG Version 4.1.0

Compiled with g++ [arm-unknown-linux-gnueabihf]

Configured options: +pcre

Please see https://www.swig.org for reporting bugs and further information
```

### macOS
```
% swig --version

SWIG Version 4.3.1

Compiled with clang++ [aarch64-apple-darwin24.2.0]

Configured options: +pcre

Please see https://www.swig.org for reporting bugs and further information
```

https://github.com/pymupdf/PyMuPDF/blob/5b6acfb369fb4c460ffeb5f2288d6efe81b93c93/setup.py#L729

[]