Pin Aesara version temporarily

[michaelosthege]

See #4961

This PR shall make the tests green again on main.

[twiecki]

Can merge when everything is green 👍.

[codecov]

Codecov Report

Merging #4963 (1334449) into main (7312736) will increase coverage by 40.80%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             main    #4963       +/-   ##
===========================================
+ Coverage   33.27%   74.08%   +40.80%     
===========================================
  Files          86       86               
  Lines       13862    13862               
===========================================
+ Hits         4613    10270     +5657     
+ Misses       9249     3592     -5657     

Impacted Files	Coverage Δ
pymc3/variational/opvi.py	30.29% <0.00%> (+0.48%)	⬆️
pymc3/variational/approximations.py	28.98% <0.00%> (+0.63%)	⬆️
pymc3/distributions/transforms.py	92.39% <0.00%> (+1.08%)	⬆️
pymc3/step_methods/pgbart.py	18.12% <0.00%> (+1.87%)	⬆️
pymc3/tests/helpers.py	61.90% <0.00%> (+4.76%)	⬆️
pymc3/variational/inference.py	29.37% <0.00%> (+7.90%)	⬆️
pymc3/vartypes.py	100.00% <0.00%> (+8.33%)	⬆️
pymc3/distributions/distribution.py	81.88% <0.00%> (+9.42%)	⬆️
pymc3/variational/callbacks.py	46.93% <0.00%> (+10.20%)	⬆️
pymc3/distributions/dist_math.py	88.23% <0.00%> (+11.22%)	⬆️
... and 47 more