🐛 Source Pennylane: fix available sync strategies for stream `category_groups`

[keurcien]

What

The category_groups endpoint does actually return an updated_at field which means incremental sync is not supported.

How

• Remove the parts of the manifest that are related to the incremental sync configuration for the category_groups stream.

Review guide

User Impact

The user will use the correct sync strategy to replicate the category_groups records.

Can this PR be safely reverted and rolled back?

• [x] YES 💚
• [ ] NO ❌