deps: require juliacall 0.9.37

[MilesCranmerBot]

Why

juliacall 0.9.37 (PythonCall.jl 0.9.37) adds Python 3.15 support for conda-forge's Python, which no longer ships its shared library inside the python package (JuliaPy/PythonCall.jl#838, #839).

Scope

• juliacall>=0.9.37,<0.9.38 in pyproject.toml (was >=0.9.36,<0.9.37).
• pyjuliacall>=0.9.37,<0.9.38 in environment.yml (was >=0.9.29,<0.9.36, already out of step with pyproject.toml).

Tradeoffs

Draft until both of these exist:

• juliacall 0.9.37 on PyPI (and pyjuliacall 0.9.37 on conda-forge for environment.yml);
• a SymbolicRegression.jl 2.7.x release containing deps: require PythonCall 0.9.37 SymbolicRegression.jl#770, which moves its exact PythonCall pin from 0.9.36 to 0.9.37. juliacall 0.9.37 requires exactly PythonCall 0.9.37, so until then the Julia environment cannot resolve. pysr/juliapkg.json already accepts any ~2.7.0 release, so no change is needed there.

Blast Radius

Users holding juliacall 0.9.36 alongside PySR must upgrade it.

Verification

CI, once the two releases above are out.