Segfault when passing in filepaths as CLI args

In main.zig:
```zig
var files: std.ArrayList([]const u8) = .empty;
    defer {
        for (files.items) |file| allocator.free(file); // <--- Segfault here due to the string being an arg and not something allocated during collectSpecFiles
        files.deinit(allocator);
    }
    try collectSpecFiles(allocator, &files, res);
```