Replace 100MB Cloudflare speedtest URL with 99MB

[taskmgr818]

fix #9071
找了半天别的测速源，最后发现改成 99999999 就行……

curl -I "https://speed.cloudflare.com/__down?bytes=99999999"
# HTTP/1.1 200 OK

[Copilot]

Pull request overview

This PR addresses Issue #9071 where the Cloudflare 100MB speedtest URL returns 403 Forbidden without a Referer header, by switching the 100MB test source to Cachefly to keep the speed test feature working without adding headers across the codebase.

Changes:

• Added Cachefly 100MB test URL to the SpeedTestUrls list.
• Removed Cloudflare 100MB URL (bytes=100000000) from the SpeedTestUrls list.

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[Copilot]

Removing the Cloudflare 100MB URL from SpeedTestUrls won’t fix existing users who already have SpeedTestItem.SpeedTestUrl persisted as https://speed.cloudflare.com/__down?bytes=100000000; ConfigHandler.LoadConfig() only sets a default when the value is empty, so those configs will still hit 403 and speedtest will keep failing. Consider adding a small migration/normalization step during config load (e.g., if the saved URL equals the removed Cloudflare 100MB URL, replace it with the new Cachefly 100MB URL) so the bug is resolved without requiring manual user intervention.

[yfdyh000]

批量测速会触发HTTP 429错误。

[2dust]

批量测速会触发HTTP 429错误。

有什么解决办法？

[yfdyh000]

批量测速会触发HTTP 429错误。

有什么解决办法？

不清楚，只是昨天看到了一次。似乎无法稳定重现。

[AoiNyanko]

批量测速会触发HTTP 429错误。

有什么解决办法？

不清楚，只是昨天看到了一次。似乎无法稳定重现。

加個Ref RequestHeader就能繼續100MB了, 很神奇

[yfdyh000]

批量测速会触发HTTP 429错误。

有什么解决办法？

https://sea-repo.hostwinds.net/tests/100mb.zip 可以用。但如果放到软件里，我不确定能撑多久。