fix: mention toga

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

Author: henryiii

peps/pep-0808.rst

@@ -115,7 +115,9 @@ cases that have come up:
   making an all dependency, or reading dependencies from dependency-groups, for
   example). Adding constraints can also be useful; pybind11_ uses adds a ``global``
   extra that pins ``pybind11-global==<version>``, as both packages are in the
-  same repository and released in sync.
+  same repository and released in sync. toga_ is a collection of packages that
+  currently is unable to set any static dependencies due to the same sort of
+  pinning problem.
 - Adding classifiers; some backends can compute classifiers from other places
   and inject them (Poetry_ being the best known example).
 - Adding license files to the wheel based on what libraries are linked in (this
@@ -416,6 +418,7 @@ References
 .. _pybind11: https://github.com/pybind/pybind11
 .. _Poetry: https://python-poetry.org/
 .. _setuptools: https://github.com/pypa/setuptools
+.. _toga: https://github.com/beeware/toga
 
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