MPowerSeries: Don't go through symbolics to compute exp(0), log(1)

[mkoeppe]

• Part of: Meta-ticket: Modularize sagelib into separate distributions (pip-installable packages) sagemath-... for Sage 10.x #29705
• Cherry-picked from: Modularization of sagelib: Distributions sagemath-{brial,combinat,eclib,flint,gap,giac,glpk,graphs,groups,homfly,lcalc,libbraiding,libecm,linbox,modules,mpmath,ntl,pari,plot,polyhedra,schemes,singular,standard-no-symbolics,symbolics} #35095

📝 Checklist

• The title is concise, informative, and self-explanatory.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation accordingly.

⌛ Dependencies

• Depends on Fix Python package metadata generated by bootstrap #36240 (merged here)
• Depends on Fix setuptools version bounds in generated pyproject.toml files #36263 (merged here)

[orlitzky]

You can avoid SR with g.exp() here and likewise in the other examples.

[mkoeppe]

Actually this error does not come from going through SR but illustrates that exp(2) does not exist in the base ring.

2 of the other # needs sage.symbolic turned out to be unnecessary due to advances in modularization. Removed in 7dde129

[github-actions]

Documentation preview for this PR (built with commit e2a76d2; changes) is ready! 🎉

[orlitzky]

Ok, LGTM. I personally prefer foo.is_zero() to not foo since the latter can hide errors, but I'm not losing sleep over it.

[mkoeppe]

Thanks!