Why can't set variables related collation as utf8mb4_unicode_ci?

[li lida]

Show mysql version here:

mysql --version
mysql Ver 15.1 Distrib 10.5.11-MariaDB, for debian-linux-gnu (x86_64) using EditLine wrapper

And my mariadb's configuration file.

cat /etc/mysql/mariadb.cnf
[client]
default-character-set = utf8mb4
[mysql]
default-character-set = utf8mb4
[mysqld]

character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect = 'SET NAMES utf8mb4'
init_connect = 'SET collation_connection = utf8mb4_unicode_ci'


[client-server]
socket = /run/mysqld/mysqld.sock

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mariadb.conf.d/

Enter into mysql,issue command `show variables like 'collation%';`:

+----------------------+--------------------+
| Variable_name | Value |
+----------------------+--------------------+
| collation_connection | utf8mb4_general_ci |
| collation_database | utf8mb4_general_ci |
| collation_server | utf8mb4_general_ci |
+----------------------+--------------------+
3 rows in set (0.001 sec)

How can get the below result?

+----------------------+--------------------+
| Variable_name | Value |
+----------------------+--------------------+
| collation_connection | utf8mb4_unicode_ci |
| collation_database | utf8mb4_unicode_ci |
| collation_server | utf8mb4_unicode_ci |
+----------------------+--------------------+
3 rows in set (0.001 sec)