fix: widen pydantic-core bound via fern 5.14.8 regen (closes #701) (#724)

SDK regeneration for 2026-06-02.

## Generator bump
`fernapi/fern-python-sdk` **5.8.3 → 5.14.8** (set in
`deepgram-docs/fern/generators.yml`). SDK version `7.1.2 → 7.3.1`.

## Headline fix — closes #701, supersedes #723
The new generator widens the `pydantic-core` bound from
`>=2.18.2,<2.44.0` to `>=2.18.2,<3.0.0` in both `pyproject.toml` and
`requirements.txt`, and regenerates `poetry.lock` (now resolves
`pydantic-core 2.46.4`). This fixes the resolver conflict with
`pydantic>=2.13` at the generator level, so the manual one-line patch in
#723 is no longer needed.

## Manual patches reconciled
All 20 temporarily-frozen files were diffed (`.bak` vs regenerated). The
generator caught up on **none** of them, so all 20 patches were
re-applied and re-frozen in `.fernignore`:
- `core/query_encoder.py` — bool→lowercase coercion for websocket query
strings
- 4 socket clients — broad `except Exception`, optional control-message
params, agent `_sanitize_numeric_types`, listen/v2 `send_configure` raw
shim
- 7 agent-settings type/request files — back-compat for the 2026-05-05
schema restructure (callable `AgentV1SettingsAgent(...)`, legacy
`messages=`/nested-context remap, `.messages` read access, `str` audio
container). Note: 5.14.8 now natively types `AgentV1SettingsAgent =
Union[AgentV1SettingsAgentContext, str]`; the callable-class shim is
retained for constructor back-compat.
- 7 package `__init__.py` files — legacy alias re-exports (no new
generator entries to merge; all showed `new+:0`)
- `tests/wire/test_manage_v1_projects_keys.py` — legacy create-key alias
wire coverage

## Verification
- `poetry run mypy src/` — clean (801 files)
- `poetry run pytest -rP .` — 222 passed, 4 skipped (incl. all custom
back-compat regression tests)
- Pre-existing ruff findings in `tests/manual`/`tests/custom` are
unchanged and not CI-gated.

---------

Co-authored-by: fern-api <115122769+fern-api[bot]@users.noreply.github.com>