Avoid ignoring misspelled tables in pixi.toml

[ruben-arts]

Problem description

Typo's in the table names of the pixi.toml should warn the user of using an unknown table.

In my case the following table was ignored without warning me so I had to keep looking to find what the issue was. A warning could have saved me 30minutes.

The following should give me an warning or even an error:

[dependenies]
python = "*"