fix: 修复 pure-ftpd 上传缓慢问题

[bh1xaq]

What this PR does / why we need it?

pure-ftpd 上传缓慢是由于 login 过程中 Argon2id 算法的密码校验导致的，所以通过调整加密算法来处理 FTP 上传过程中的卡顿问题。

The slow upload in pure-ftpd is due to the Argon2id algorithm used for password verification during the login process. To address the lag in the FTP upload process, consider adjusting the encryption algorithm.

Summary of your change

调整了 pure-ftpd 加密算法，由 Argon2id 变更为 Bcrypt，已达到安全和速度的平衡。
影响范围：新增和修改用户密码，将不在使用原生 pure-pw 命令。其他操作不影响。

The encryption algorithm in pure-ftpd has been changed from Argon2id to Bcrypt, achieving a balance between security and speed.
Scope of impact: This change affects only the creation and modification of user passwords, which will no longer use the native pure-pw command. Other operations are unaffected.

Please indicate you've done the following:

• [✅] Made sure tests are passing and test coverage is added if needed.
• [✅] Made sure commit message follow the rule of Conventional Commits specification.
• [✅] Considered the docs impact and opened a new docs issue or PR with docs changes if needed.