Allow options to disable user ssh keys configuration from the interface on app.ini (#29447)

Follow #29275
Extract from #20549
Fix #24716

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Co-authored-by: delvh <dev.lh@web.de>
(cherry picked from commit 8e12ba34bab7e728ac93ccfaecbe91e053ef1c89)

Conflicts:
	custom/conf/app.example.ini
	trivial context conflict

docs/content/administration/config-cheat-sheet.en-us.md

@@ -518,9 +518,10 @@ And the following unique queues:
 
 - `DEFAULT_EMAIL_NOTIFICATIONS`: **enabled**: Default configuration for email notifications for users (user configurable). Options: enabled, onmention, disabled
 - `DISABLE_REGULAR_ORG_CREATION`: **false**: Disallow regular (non-admin) users from creating organizations.
-- `USER_DISABLED_FEATURES`: **_empty_** Disabled features for users, could be `deletion`, `manage_gpg_keys` and more features can be added in future.
+- `USER_DISABLED_FEATURES`: **_empty_** Disabled features for users, could be `deletion`, `manage_ssh_keys`, `manage_gpg_keys` and more features can be added in future.
   - `deletion`: User cannot delete their own account.
-  - `manage_gpg_keys`: User cannot configure gpg keys
+  - `manage_ssh_keys`: User cannot configure ssh keys.
+  - `manage_gpg_keys`: User cannot configure gpg keys.
 
 ## Security (`security`)
 

docs/content/administration/config-cheat-sheet.zh-cn.md

@@ -497,9 +497,10 @@ Gitea 创建以下非唯一队列：
 
 - `DEFAULT_EMAIL_NOTIFICATIONS`: **enabled**：用户电子邮件通知的默认配置（用户可配置）。选项：enabled、onmention、disabled
 - `DISABLE_REGULAR_ORG_CREATION`: **false**：禁止普通（非管理员）用户创建组织。
-- `USER_DISABLED_FEATURES`:**_empty_** 禁用的用户特性，当前允许为空或者 `deletion`，`manage_gpg_keys` 未来可以增加更多设置。
+- `USER_DISABLED_FEATURES`:**_empty_** 禁用的用户特性，当前允许为空或者 `deletion`，`manage_ssh_keys`， `manage_gpg_keys` 未来可以增加更多设置。
   - `deletion`: 用户不能通过界面或者API删除他自己。
-  - `manage_gpg_keys`: 用户不能配置 GPG 密钥
+  - `manage_ssh_keys`: 用户不能通过界面或者API配置SSH Keys。
+  - `manage_gpg_keys`: 用户不能配置 GPG 密钥。
 
 ## 安全性 (`security`)