docs(deps): drop pickleshare and explicit ipython from docs group

Both were only needed by the old IPython.sphinxext.ipython_directive,
which myst-nb replaced. pickleshare (IPython %store, abandoned 2018) has
no remaining consumer. ipython is now pulled transitively by ipykernel
and myst-nb, so the explicit floor is redundant. Relocked.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: timsaucer

pyproject.toml

@@ -224,14 +224,12 @@ dev = [
 # from sdist under free-threaded interpreters (PyO3 < 3.14 support).
 release = ["pygithub==2.5.0"]
 docs = [
-  "ipython>=8.12.3",
   "jinja2>=3.1.5",
   # myst-nb supersedes myst-parser: MyST markdown parsing plus executable
   # `{code-cell}` notebook directives. Pulls myst-parser, ipykernel, and the
   # jupyter execution stack transitively.
   "myst-nb>=1.1",
   "pandas>=2.0.3",
-  "pickleshare>=0.7.5",
   "pydata-sphinx-theme>=0.16,<0.17",
   "setuptools>=75.3.0",
   "sphinx-autoapi>=3.4.0",