deps: remove unused Pydantic email extra

[nabinchha]

Priority Level

Low

Task Summary

Remove the unused email-validator runtime dependency by replacing the pydantic[email] dependency with plain pydantic in data-designer-config.

Implementation

The email-validator dependency is being removed in NVIDIA-NeMo/DataDesigner#824.

Technical Details & Implementation Plan

• Change pydantic[email]>=2.9.2,<3 to pydantic>=2.9.2,<3 in packages/data-designer-config/pyproject.toml.
• Regenerate uv.lock.
• Confirm email-validator and dependencies used only by that extra are removed from the locked runtime closure when no other package requires them.
• Run the config package tests and the full test suite.
• If the dependency-license policy from ci: add dependency license compatibility check #822 has landed, remove the package-specific email-validator exception.

Acceptance Criteria

• Production code and tests continue to pass without the Pydantic email extra.
• email-validator is no longer a Data Designer runtime dependency.
• The lockfile reflects the reduced dependency graph.
• The dependency-license policy contains no stale email-validator exception.

Investigation / Context

email-validator is currently pulled in by:

"pydantic[email]>=2.9.2,<3"

No production use was found for pydantic.EmailStr, NameEmail, email_validator, or validate_email. Data Designer's synthetic email generation uses its own string-generation logic and does not depend on email validation.

The only explicit email_validator import is in a synthetic dependency-audit test fixture, not application code.

Related: #822

Agent Plan / Findings

Repository and GitHub searches found no existing issue, PR, or discussion proposing removal of this dependency. Issue #822 references email-validator only as a license-policy exception and is not a duplicate.

Dependencies

None. Coordinate exception cleanup with #822 if that work lands first.