Fix invalid_data_error! macro to properly format error messages with arguments

[sile]

The invalid_data_error! macro was dropping variadic format arguments ($arg), so error messages lost runtime context (for example, values like method=0).

Changes

• Fixed the single-argument arm to construct InvalidData errors directly.
• Fixed the variadic arm for std builds to format messages with ::alloc::format!($fmt, ...).
• Added cfg handling so no_std builds remain compatible with core2::io::Error::new (which requires &'static str in that mode).
• Added a regression test for issue invalid_data_error drops $arg #82 (zlib::tests::issue_82) to ensure formatted values appear in error messages.

Closes #82