test(langchain): Replace mocks with httpx types

[alexander-alderman-webb]

Description

Replace mocks with httpx types to avoid test failures when library internals change.

Issues

Reminders

• Please add tests to validate your changes, and lint your code using tox -e linters.
• Add GH Issue ID & Linear ID (if applicable)
• PR title should use conventional commit style (feat:, fix:, ref:, meta:)
• For external contributors: CONTRIBUTING.md, Sentry SDK development docs, Discord community

[github-actions]

Semver Impact of This PR

🟢 Patch (bug fixes)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

---

New Features ✨

• (asgi) Add option to disable suppressing chained exceptions by alexander-alderman-webb in #5714
• (logging) Separate ignore lists for events/breadcrumbs and sentry logs by sl0thentr0py in #5698

Bug Fixes 🐛

Anthropic

• Set exception info on streaming span when applicable by alexander-alderman-webb in #5683
• Patch AsyncStream.close() and AsyncMessageStream.close() to finish spans by alexander-alderman-webb in #5675
• Patch Stream.close() and MessageStream.close() to finish spans by alexander-alderman-webb in #5674

Other

• (starlette) Catch Jinja2Templates ImportError by alexander-alderman-webb in #5741

Documentation 📚

• Add note on AI PRs to CONTRIBUTING.md by sentrivana in #5696

Internal Changes 🔧

Langchain

• Replace mocks with httpx types by alexander-alderman-webb in #5724

• Consolidate available tools assertion by alexander-alderman-webb in #5721
• Consolidate span origin assertion by alexander-alderman-webb in #5723

Other

• Add -latest alias for each integration test suite by sentrivana in #5706
• Use date-based branch names for toxgen PRs by sentrivana in #5704
• 🤖 Update test matrix with new releases (03/19) by github-actions in #5703
• Add client report tests for span streaming by sentrivana in #5677

Other

• Update CHANGELOG.md by sentrivana in #5685

---

_{🤖 This preview updates automatically when you update the PR.}

[github-actions]

Codecov Results 📊

✅ 54 passed | ⏭️ 2 skipped | Total: 56 | Pass Rate: 96.43% | Execution Time: 7.44s

All tests are passing successfully.

✅ Patch coverage is 100.00%. Project has 13198 uncovered lines.

---

Generated by Codecov Action