Fix syntax errors

[gravitacia]

Here is a complete, pre-filled Pull Request template that you can copy and paste directly into the GitHub PR description:

- This fix issue: Fixes Python 3 syntax errors in exception handling.

## PR Description:

This PR corrects two Python syntax errors caused by unparenthesized multiple exception catching blocks, which are invalid in Python 3 and prevent successful byte-compilation or execution of the respective modules. 

Specifically:
- archinstall/lib/command.py: Parenthesized `PermissionError, FileNotFoundError` on line 382 to `(PermissionError, FileNotFoundError)`.
- archinstall/lib/models/network.py: Parenthesized `ValueError, IndexError` on line 234 to `(ValueError, IndexError)`.

These fixes restore compliance with standard Python 3 exception handling syntax.

## Tests and Checks
- [x] I have tested the code!<br>
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      Successfully compiled all Python modules using Python's compiler module (`py_compile`) recursively across the entire repository to verify that all modules now parse and byte-compile 100% cleanly without any syntactic or parsing errors.
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[correctmost]

The parentheses are not needed in Python 3.14: https://peps.python.org/pep-0758/