Missing imports in documentation

[stavros11]

          Maybe we should take the time to investigate this, even if probably not immediately. It could be confusing for users (as it was in #801), and maybe there is a configuration to change this behavior.

Originally posted by @alecandido in https://github.com/qiboteam/qibolab/pull/789#discussion_r1513501563

We should investigate why CI is not failing even if some doctest cells, such as https://github.com/qiboteam/qibolab/blob/595351782d55a20fa2b8c35104c000092e42f585/doc/source/main-documentation/qibolab.rst?plain=1#L392 and https://github.com/qiboteam/qibolab/blob/595351782d55a20fa2b8c35104c000092e42f585/doc/source/main-documentation/qibolab.rst?plain=1#L512 are missing imports.

[rscircus]

Ran into the same thing, hence, decided to use literal includes. See also:

• https://github.com/qiboteam/qibolab/issues/802
• with related PR: https://github.com/qiboteam/qibolab/pull/807