fix: use ConfigDict instead of class-based Config in RequestContext

[citizen204]

Summary

RequestContext in src/bedrock_agentcore/runtime/context.py uses the Pydantic V1-style inner class Config to set arbitrary_types_allowed = True. Pydantic V2 deprecated this pattern and emits a PydanticDeprecatedSince20 warning on every import of BedrockAgentCoreApp, adding noise to user applications and test suites.

Replace the inner Config class with model_config = ConfigDict(arbitrary_types_allowed=True) — the idiomatic Pydantic V2 pattern — so the warning is no longer emitted.

Fixes #320

Changes

• src/bedrock_agentcore/runtime/context.py: import ConfigDict from pydantic; replace class Config with model_config = ConfigDict(arbitrary_types_allowed=True)

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@2550d55). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #522   +/-   ##
=======================================
  Coverage        ?   89.20%           
=======================================
  Files           ?       96           
  Lines           ?     8441           
  Branches        ?     1256           
=======================================
  Hits            ?     7530           
  Misses          ?      586           
  Partials        ?      325           

Flag	Coverage Δ
unittests	89.20% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[valter-silva-au]

Nice — this is the idiomatic V2 pattern and matches the existing model_config = ConfigDict(...) usage elsewhere in the repo (e.g. evaluation/runner/dataset_types.py).

One suggestion to lock it in: add a regression test in tests/.../runtime/test_context.py that instantiates RequestContext under warnings.catch_warnings() + warnings.simplefilter("error") and asserts no PydanticDeprecatedSince20 warning is raised. That guards against the class-based Config silently creeping back in, and gives the fix a failing-before/passing-after anchor. Otherwise LGTM.