FIX: register auto-generated pyrit_auxiliary_attacks API page in myst.yml

This PR adds an `__init__.py` to `pyrit.auxiliary_attacks` (to emit the
`ExperimentalWarning` on import), which made the package visible to
`build_scripts/gen_api_md.py` and caused it to generate a new
`doc/api/pyrit_auxiliary_attacks.md` reference page.

After PR microsoft#1793 added fail-fast TOC validation, any generated API page
that is missing from `doc/myst.yml` fails the `deploy-book` job. Add
the entry to the alphabetically-correct slot (between `pyrit_auth.md`
and `pyrit_cli_api_client.md`) so the page is exposed in the Jupyter
Book TOC.

Also refresh `uv.lock` to pick up the `exceptiongroup>=1.2.0;
python_version < '3.11'` requirement that landed on `main`.

Verified locally: `python build_scripts/gen_api_md.py` reports
`Validated 179 file references in myst.yml` and `No orphaned
documentation files found`; `cd doc && uv run jupyter-book build --all
--html --strict` exits 0.

The other red check on the previous run, `Build Production (local)`,
failed with `Upload progress stalled.` during the artifact upload
step. That is a GitHub Actions infrastructure flake unrelated to this
PR; it will resolve when CI re-runs against this commit.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: romanlutz

doc/myst.yml

@@ -205,6 +205,7 @@ project:
       children:
         - file: api/pyrit_analytics.md
         - file: api/pyrit_auth.md
+        - file: api/pyrit_auxiliary_attacks.md
         - file: api/pyrit_cli_api_client.md
         - file: api/pyrit_cli_pyrit_scan.md
         - file: api/pyrit_cli_pyrit_shell.md