Remove unused email-validator dependency

[sea-kelp]

Description of Changes

email-validator was added as a dependency in this commit but does not appear to ever have been used. This change removes the unused dependency.

Notes for Deployment

None!

Screenshots (if appropriate)

N/A

Tests and linting

• I have rebased my changes on main

• just lint passes

• just test passes

[sea-kelp]

Looks like email_validator is used indirectly by wtforms for email validation

/usr/local/lib/python3.11/site-packages/wtforms/validators.py:393: in __init__
    raise Exception("Install 'email_validator' for email validation support.")
E   Exception: Install 'email_validator' for email validation support.