Disable %jsroot magic in notebook when TWebCanvas is not compiled

### Feature description

TWebCanvas functionality is required to produce data for JSROOT plotting in jupyter notebooks.
If it does not compiled - `%jsroot off` should be a default option.
This can be changed via system.rootrc file.

Addressing https://root-forum.cern.ch/t/64390/

### Alternatives considered

_No response_

### Additional context

_No response_