[smigolsmigol]

The integration job previously covered one known Pydantic regression from the repository checkout. This expands it into a small issue-derived matrix and runs the checks from the built wheel, matching how users install Bumpcheck.

The matrix covers:

• 2.11 regression: Strict causes a field to not be validated properly pydantic/pydantic#11681: strict mapping-key validation changes
• 2.12.0: create_model() ignores modified FieldInfo.default in v2.12, causing fields to become required pydantic/pydantic#12360: the FieldInfo default regression, both directly and through Instructor partial streaming
• 2.12.0: field_serializer not called by model_dump(mode='json', serialize_as_any=True) in v2.12 pydantic/pydantic#12379: the serialize_as_any regression in 2.12.0, plus an unchanged control using the fixed 2.12.5 release

Tag pushes no longer repeat the full CI suite; tagged releases continue to use the dedicated release workflow.

Validation:

• 65 unit tests passed, with the five integration cases skipped outside the integration job
• all five issue-derived cases passed from the built wheel
• Ruff check and format passed
• branch coverage: 96%