Refactor : src/utils/dateFormatter.test.tsfrom jest to vitest

[syedali237]

Is your feature request related to a problem? Please describe.

This file is currently tested using Jest. As part of our migration to Vitest, we need to refactor the file's test cases to align with Vitest's syntax and features.

Acceptance Criteria

1. Replace Jest-specific functions and mocks with Vitest equivalents
2. Rename the test file from having a .test.* suffix to a .spec.* suffix
3. Ensure all tests in the file pass after migration using npm run test:vitest
4. Maintain the test coverage for the file as 100% after migration
5. Upload a video or photo for this specific file coverage is 100% in the PR description

Additional context

1. Refer to the merged PR for the base Vitest configuration:
   https://github.com/PalisadoesFoundation/talawa-admin/pull/2457/files#diff-9a5a35cf8d7f02b2bba90905714b762560579c4789e9eb4cebb4607980aa3d93
2. Vitest reference site:
   https://vitest.dev/

Potential internship candidates

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• Student Internship Programs talawa#359

[syedali237]

assign this to me.

[varshith257]

@syedali237 Here you go.