PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines
• Tests for the changes have been added
• Docs have been added / updated

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• angular.dev application / infrastructure changes
• Other... Please describe:

What is the current behavior?

email() and pattern() only accept SchemaPath<string, ...> types, which causes TypeScript errors when optional fields are represented as string | null.

Issue Number: #66539

What is the new behavior?

Updates email() and pattern() validators to support nullable string paths.

A type test was also added to verify usage with string | null.

Runtime behavior is unchanged because nullable values were already treated as empty values.

Does this PR introduce a breaking change?

• Yes
• No

Other information

None.