br: remove experimental feature notice for encryption

Signed-off-by: Wenqi Mou <[email protected]>

br/br-pitr-manual.md

@@ -91,10 +91,6 @@ tiup br log start \
 
 ### Encrypt the log backup data
 
-> **Warning:**
->
-> Currently, this feature is experimental. It is not recommended that you use it in production environments. If you find a bug, you can report an [issue](https://github.com/pingcap/tidb/issues) on GitHub.
-
 BR enables you to encrypt log backup data before uploading it to your backup storage.
 
 Starting from TiDB v8.4.0, you can encrypt log backup data by passing the following parameters in the log backup command, which is similar to [snapshot backup encryption](/br/br-snapshot-manual.md#encrypt-the-backup-data):

br/br-snapshot-manual.md

@@ -135,10 +135,6 @@ When the backup and restore feature backs up data, it stores statistics in JSON
 
 ## Encrypt the backup data
 
-> **Warning:**
->
-> This is an experimental feature. It is not recommended that you use it in the production environment.
-
 BR supports encrypting backup data at the backup side and [at the storage side when backing up to Amazon S3](/br/backup-and-restore-storages.md#amazon-s3-server-side-encryption). You can choose either encryption method as required.
 
 Since TiDB v5.3.0, you can encrypt backup data by configuring the following parameters: