Fix timesheet accordion background in dark mode

[Siddhantsingh1230]

Description

This PR fixes timesheet accordion background in dark mode when hovering over a timesheet.

Relevant Technical Choices

• Add subtle slate TW class dark:hover:bg-slate-800

Testing Instructions

• Go to Team page
• Search for a user
• Open Timesheet Accordion for the user
• Hover over any timesheet in (light/dark) any mode

Additional Information:

N/A

Screenshot/Screencast

Checklist

• I have carefully reviewed the code before submitting it for review.
• This code is adequately covered by unit tests to validate its functionality.
• I have conducted thorough testing to ensure it functions as intended.
• A member of the QA team has reviewed and tested this PR (To be checked by QA or code reviewer)