move solara_viz back to experimental

[Corvince]

Move the current SolaraViz back into experimentals. This way users of Mesa 2.x that already adapted their frontend can continue to use it. But we will provide a different, stable API for Mesa 3 in #2263

Follow-up PRs should include a deprecation warning and link to a migration guide from the experimental SolaraViz to the new SolaraViz (to be written)

[github-actions]

Performance benchmarks:

Model	Size	Init time [95% CI]	Run time [95% CI]
BoltzmannWealth	small	🔴 +14.2% [+11.9%, +16.3%]	🔴 +21.8% [+21.6%, +21.9%]
BoltzmannWealth	large	🔵 -3.7% [-22.3%, +14.6%]	🔴 +34.1% [+30.3%, +37.8%]
Schelling	small	🔴 +16.5% [+16.1%, +16.9%]	🔴 +26.1% [+25.8%, +26.4%]
Schelling	large	🔴 +16.8% [+16.0%, +17.6%]	🔴 +23.3% [+21.6%, +24.9%]
WolfSheep	small	🔴 +16.6% [+15.5%, +17.6%]	🔴 +18.7% [+18.5%, +19.0%]
WolfSheep	large	🔴 +17.9% [+17.5%, +18.3%]	🔴 +20.4% [+19.6%, +21.1%]
BoidFlockers	small	🔴 +15.1% [+14.2%, +16.1%]	🔴 +7.8% [+7.0%, +8.5%]
BoidFlockers	large	🔴 +13.9% [+13.0%, +14.8%]	🔴 +11.7% [+11.1%, +12.4%]

[EwoutH]

Right, I like this.

Warning can be added once new-new viz is semi-stable.

[EwoutH]

Maybe we can also revert it back to JupyterViz. And then we can simply revert projectmesa/mesa-examples#155.

Edit: There are a few more places where this needs to be changed, see:

• Set JupyterViz as stable #2090
• Rename JupyterViz to SolaraViz #2187

[Corvince]

SolaraViz and JupyterViz both work. But the examples need to be updated anyway, so not sure.

By the way I can take care of updating the examples. This way I get a better feeling on how the frontend is used and directly fix anything that's missing

[Corvince]

@rht do you agree with this approach? Would like to have your approval before merging

[rht]

I agree.

[EwoutH]

This PR did break the CI, unfortunately:

__________________ ERROR collecting tests/test_solara_viz.py ___________________
ImportError while importing test module '/home/runner/work/mesa/mesa/tests/test_solara_viz.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/opt/hostedtoolcache/Python/3.12.5/x64/lib/python3.12/importlib/__init__.py:90: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
tests/test_solara_viz.py:8: in <module>
    from mesa.visualization.solara_viz import Slider, SolaraViz, UserInputs
E   ModuleNotFoundError: No module named 'mesa.visualization.solara_viz'

The test_solara_viz.py should be updated.