fix(pydantic-ai): Remove agent stack context variable

[alexander-alderman-webb]

Description

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

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Semver Impact of This PR

🟢 Patch (bug fixes)

📋 Changelog Preview

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New Features ✨

• (integrations) Instrument pyreqwest tracing by servusdei2018 in #5682

Bug Fixes 🐛

Pydantic Ai

• Remove agent stack context variable by alexander-alderman-webb in #5958

• Determine if response is streamed based on the method by alexander-alderman-webb in #5957

Internal Changes 🔧

Pydantic Ai

• Remove dead Model.request patch by alexander-alderman-webb in #5956
• Consolidate binary blob redaction tests to stop relying on SDK internals by alexander-alderman-webb in #5946

Other

• (openai) Split token counting by API for easier deprecation by ericapisani in #5930
• (opentelemetry) Ignore mypy error by alexander-alderman-webb in #5927
• Fix license metadata in setup.py by sl0thentr0py in #5934
• Update validate-pr workflow by stephanie-anderson in #5931

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Codecov Results 📊

✅ 14 passed | Total: 14 | Pass Rate: 100% | Execution Time: 3.12s

All tests are passing successfully.

❌ Patch coverage is 0.00%. Project has 15908 uncovered lines.

Files with missing lines (5)

File	Patch %	Lines
ai_client.py	0.00%	⚠️ 145 Missing
tools.py	0.00%	⚠️ 88 Missing
agent_run.py	0.00%	⚠️ 86 Missing
invoke_agent.py	0.00%	⚠️ 81 Missing
utils.py	0.00%	⚠️ 78 Missing

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