Loosen dependency requirements

[giro090]

The requirements in the .toml are very recent package versions, and users particularly in other departments may not have access to these.

It would be good to loosen the requirements as much as we can within the scope of the current functionality of gptables to ensure max compatibility with other package versions.

Definition of done:

• Compatibility of lower dependency versions is investigated, particularly pandas and XlsxWriter.
• Tests continue to pass and functionality is preserved.
• The pyproject.toml is updated.