Support for powm1 from scipy.special in codegen

[bjodah]

References to other Issues or PRs

NIL

Brief description of what is fixed or changed

Upcoming scipy 1.10.0 has support for powm1, so does the boost c++ library since long. This PR adds a Function subclass for this entity and rewrite rules for it.

Other comments

Release Notes

• codegen
  • powm1 is now available for this enhanced precision math function.

[sympy-bot]

✅

Hi, I am the SymPy bot (v167). I'm here to help you write a release notes entry. Please read the guide on how to write release notes.

Your release notes are in good order.

Here is what the release notes will look like:

• codegen
  • powm1 is now available for this enhanced precision math function. (#24300 by @bjodah)

This will be added to https://github.com/sympy/sympy/wiki/Release-Notes-for-1.12.

Click here to see the pull request description that was parsed.

<!-- Your title above should be a short description of what
was changed. Do not include the issue number in the title. -->

#### References to other Issues or PRs
<!-- If this pull request fixes an issue, write "Fixes #NNNN" in that exact
format, e.g. "Fixes #1234" (see
https://tinyurl.com/auto-closing for more information). Also, please
write a comment on that issue linking back to this pull request once it is
open. -->
NIL

#### Brief description of what is fixed or changed
Upcoming scipy 1.10.0 has support for [powm1](https://scipy.github.io/devdocs/reference/generated/scipy.special.powm1.html), so does the boost c++ library since long. This PR adds a `Function` subclass for this entity and rewrite rules for it.

#### Other comments


#### Release Notes

<!-- Write the release notes for this release below between the BEGIN and END
statements. The basic format is a bulleted list with the name of the subpackage
and the release note for this PR. For example:

* solvers
  * Added a new solver for logarithmic equations.

* functions
  * Fixed a bug with log of integers.

or if no release note(s) should be included use:

NO ENTRY

See https://github.com/sympy/sympy/wiki/Writing-Release-Notes for more
information on how to write release notes. The bot will check your release
notes automatically to see if they are formatted correctly. -->

<!-- BEGIN RELEASE NOTES -->
* codegen
  * `powm1` is now available for this enhanced precision math function.
<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

[bjodah]

I do not understand why flake8 (test / code-quality) started complaining after 5278b0f?

[oscarbenjamin]

I do not understand why flake8 (test / code-quality) started complaining after 5278b0f?

I think it's just a new version of flake8. The 6.0.0 release was 2 hours ago:
https://pypi.org/project/flake8/#history

[oscarbenjamin]

Looks good.

[oscarbenjamin]

Looks like mpmath has powm1 as well:
https://mpmath.org/doc/current/functions/powers.html#powm1

Maybe that should be used in e.g. evalf/lambdify etc.