Temporarily disable typehints and singledispatch in function signatures

[IvanIsCoding]

Closes #504

Temporarily disables the typehints and single dispatch in functions signatures until Qiskit/qiskit_sphinx_theme#21 is fixed.

Currently, the hints only appear on the functions with single dispatch and only appear for the graph argument. Because we already document that those functions accept both PyGraph and PyDiGraph, I argue that we do not lose much by disabling the hints.

Here is what the documentation looks like after the PR is applied:

[coveralls]

Pull Request Test Coverage Report for Build 2286936931

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 97.175%

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Totals
Change from base Build 2283131205:	0.0%
Covered Lines:	11626
Relevant Lines:	11964

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💛 - Coveralls

[georgios-ts]

Looks nice! It's an easy and quick fix. I agree we don't lose any information by dropping the type hints.

If we're going down this path, we could also leverage autodoc-before-process-signature and unregister PyGraph, PyDiGraph from the single dispatch functions when building the docs. https://stackoverflow.com/questions/25951651/unregister-for-singledispatch. In this way we'll avoid the repetition of the signatures.

[IvanIsCoding]

Looks nice! It's an easy and quick fix. I agree we don't lose any information by dropping the type hints.

If we're going down this path, we could also leverage autodoc-before-process-signature and unregister PyGraph, PyDiGraph from the single dispatch functions when building the docs. https://stackoverflow.com/questions/25951651/unregister-for-singledispatch. In this way we'll avoid the repetition of the signatures.

I tried unregistering but it makes the docs fail because we still need to use some of the methods in jupyter-execute.

I also tried using autodoc-process-signature to filter the signatures and I ended up with the normal signature and two blank signatures, it did not filter out the signatures unfortunately.

I pushed a trick that should be harmless to the code and tricks Sphinx. It is 100% implementation dependant on this check from Sphinx, but it gets the job done.

Let me know what you think of the trick. The documentation now looks like this:

[georgios-ts]

Looks good! It's a bit hacky but it works :)