LITE-33583: Migrate to pydantic v2

[pcaro]

Summary

Migrates connect-eaas-core from pydantic v1 to v2 (^2.9), resolving the v1 deprecation warnings that Python 3.13/3.14 emit — the follow-up flagged in #125.

Note: this re-lands the work from #127. That PR was merged into the #125 branch rather than master, and #125 reached master with only the Python 3.13/3.14 support, so the pydantic v2 changes never made it to master. This PR is the same three commits, rebased directly onto master.

Along the way it also widens the fastapi range and fixes a packaging gap that only surfaces once we run on pydantic v2.

Changes

pydantic v1 → v2

Models (proto.py, inject/models.py, validation/models.py)

• Every Optional field gets an explicit = None default — in v2 Optional no longer implies a default, so these would otherwise become required and break deserialization.
• Message.data (discriminated union incl. None) now defaults to None, so omitting it keeps working (e.g. shutdown messages).
• BaseModel.__repr_args__ drops the removed pydantic.utils.DUNDER_ATTRIBUTES import and reads field metadata via type(self).model_fields. Sensitive-field obfuscation is unchanged.
• self.dict() → self.model_dump() (serialize); context.dict() → context.model_dump().

Tests

• v2 tightened BaseModel.__eq__ (a model no longer equals a plain dict), so schedulable/transformation assertions compare model_dump() output.
• .dict() → .model_dump().

fastapi range: ^0.115.0 → >=0.115,<0.137

fastapi began requiring pydantic v2 at 0.128 (its pydantic floor jumped from >=1.7.4,<3 to >=2.7), so this wider range is only reachable now that we run on pydantic v2.

Capped below 0.137: that release replaced eager route flattening in include_router with a lazy _IncludedRouter placeholder in router.routes, which breaks WebApplicationBase.get_routers() (it assumes every entry is an APIRoute with .endpoint). Lifting the cap requires adapting that code to the new routing model and is tracked separately.

Declare typing-inspect

fastapi-utils 0.8.0's cbv module imports typing_inspect in its pydantic-2 code path but only declares it under its all extra. Migrating to pydantic 2 therefore makes importing connect-eaas-core crash with ModuleNotFoundError: typing_inspect for any consumer that doesn't already pull it in (e.g. connect-cli). Declared directly (matching fastapi-utils' own >=0.9,<0.10 range) rather than via fastapi-utils[all], which would also drag in pydantic-settings and sqlalchemy.

Verification

• 368 passed, flake8 clean, on pydantic 2.13.4.
• Validated at both ends of the fastapi range (0.115.x and 0.136.0).
• Reproduced the typing_inspect crash from declared deps only, then confirmed the added dependency resolves it.
• No pydantic deprecation warnings remain.

LITE-33583

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[qarlosh]

to not lose track, #127 (comment): The Pydantic v2 migration should be released as a major version bump (38.0) rather than a minor one (37.x) to prevent breaking current extensions.