fix(useTimeoutPoll): unexpected immediate execution

[jiadesen]

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⚠️ Slowing down new functions

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As the VueUse audience continues to grow, we have been inundated with an overwhelming number of feature requests and pull requests. As a result, maintaining the project has become increasingly challenging and has stretched our capacity to its limits. As such, in the near future, we may need to slow down our acceptance of new features and prioritize the stability and quality of existing functions. Please note that new features for VueUse may not be accepted at this time. If you have any new ideas, we suggest that you first incorporate them into your own codebase, iterate on them to suit your needs, and assess their generalizability. If you strongly believe that your ideas are beneficial to the community, you may submit a pull request along with your use cases, and we would be happy to review and discuss them. Thank you for your understanding.

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Description

#2355

Additional context

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🤖 Generated by Copilot at 7fa971f

Fixed a bug in useTimeoutPoll that caused the polling function to run immediately. Added an option to useTimeoutFn to delay the first execution.

🤖 Generated by Copilot at 7fa971f

• Prevent polling function from running immediately on the first call by passing { immediate: false } option to useTimeoutFn (link). This fixes a bug reported in issue chore: use tryOnScopeDispose instead of tryOnUnmounted #674 and allows the user to control when to start the polling by calling the start function returned by useTimeoutPoll.