fix: improve email validation in is-email-address method

[s21sd]

Resolves #3132.

Description

What is the purpose of this pull request?

This pull request:

• Fixes the issue with the is-email-address method, ensuring it correctly validates invalid email addresses according to standard email validation rules.
• Adds comprehensive test cases to handle edge cases and improve reliability.

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Related Issues

Does this pull request have any related issues?

This pull request:

• Resolves is-email-address method incorrectly validates invalid email addresses #3132

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Questions

Any questions for reviewers of this pull request?

No.

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Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

Before

After

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Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.
• Added new test cases to ensure proper validation functionality.
• Verified that all existing tests pass without issues.

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@stdlib-js/reviewers

[stdlib-bot]

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
assert/is-email-address	$\color{green}108/108$ $\color{green}+100.00\%$	$\color{green}4/4$ $\color{green}+100.00\%$	$\color{green}1/1$ $\color{green}+100.00\%$	$\color{green}108/108$ $\color{green}+100.00\%$

The above coverage report was generated for the changes in this PR.

[kgryte]

Thank you for submitting this PR; however, it is not RFC 2822 compliant.