chore: 7zやtyposのダウンロードをリトライする

[Hiroshiba]

内容

downloadTypos内にあるfetchをリトライするようにしてみました。

https://github.com/VOICEVOX/voicevox/actions/runs/13535774481/job/37827107361
で落ちてmerge-queueが失敗したので実装してみました。

その他

[Copilot]

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

tools/helper.ts:11

• [nitpick] The loop using 'retries - 1' might be confusing and could potentially lead to off-by-one errors if 'retries' is set to 0 or 1. Consider iterating exactly 'retries' times and moving the delay logic inside the loop to handle all attempts uniformly.

for (let i = 0; i < retries - 1; i++) {