Bump litellm to 1.86.2 and openai-agents to 0.17.4 (#1478)

* Bump litellm from 1.83.0 to 1.83.7

Bumps [litellm](https://github.com/BerriAI/litellm) from 1.83.0 to 1.83.7.
- [Release notes](https://github.com/BerriAI/litellm/releases)
- [Commits](https://github.com/BerriAI/litellm/commits)

---
updated-dependencies:
- dependency-name: litellm
  dependency-version: 1.83.7
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

* Bump litellm to 1.86.2 and openai-agents to 0.17.4, drop exclude-newer overrides

litellm 1.83.7 pinned its deps to exact versions, forcing downgrades of
click, openai, pydantic, jsonschema, and others. Bumping litellm to 1.86.2
relaxes those pins and restores the downgraded packages. Also bump
openai-agents to 0.17.4 and remove the now-unnecessary exclude-newer-package
overrides.

* Remove openai-agents exclude-newer override

The openai-agents>=0.17.1 minimum pin no longer requires bypassing the
exclude-newer cooldown: 0.17.1 through 0.17.3 are now older than the 2-week
window. Drop the override so dependency selection is governed solely by the
2-week policy. openai-agents resolves to 0.17.3 (0.17.4 is still inside the
window).

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Brian Strauch <brian@brianstrauch.com>

Author: dependabot[bot]

pyproject.toml

@@ -257,6 +257,3 @@ exclude = ["temporalio/bridge/target/**/*"]
 # Prevent uv commands from building the package by default
 package = false
 exclude-newer = "2 weeks"
-# openai-agents>=0.17.1 is newer than the exclude-newer cooldown window;
-# bypass it since the minimum version pin already constrains the package.
-exclude-newer-package = { openai-agents = false }