[Refactor]: Improve workflow list render performance

[SuaYoo]

The workflow loading state currently causes unnecessary re-renders when polling. Switching to Lit Task--and perhaps guard--should improve performance.

[SuaYoo]

Should be addressed as part of #2034

[SuaYoo]

Should be addressed as part of #2034

@emma-sg is this still relevant to keep as a separate issue?

[emma-sg]

@SuaYoo Sure, it is a separate issue that'll be addressed in the same PR.