Update notebook-connector incl. Transformers-extension version > 2.1.0

[MarleneKress79789]

Developers fixed some bugs in the TE.

Next steps

• release TE
• Update NC to use TE version > 2.1.0, see NC ticket #153
• Update a-labi-dependency notebook-connector in pyproject.toml

[ckunki]

Needs to be updated here: exasol/notebook-connector#153