fix(login): prevent multiple error toasts on login by clearing previous toasts

[SharanRP]

Proposed changes

Clear existing error toasts before showing a new login error.
This prevents many identical error messages from stacking when a user clicks "Sign In" repeatedly.
closes #5308

Types of changes

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• New feature (non-breaking change which adds functionality)
• Bugfix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices applies)

Checklist

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• I have read the CONTRIBUTING doc
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• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if appropriate)
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[PriteshKiri]

Hey @SharanRP

Thanks for raising the PR.

It looks good!! Could you just share the video for the fix?

[SharanRP]

AwesomeScreenshot-11_22_2025.11_50_39PM.webm

@PriteshKiri @amityt