Bump up the minimum required MySQL version (#25465)

MySQL 5.7 is at end of life.

https://mattermost.atlassian.net/browse/MM-55589

```release-note
We bump up minimum MySQL version to be 8.0.0
```


Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>

server/build/docker-compose.common.yml

@@ -1,7 +1,7 @@
 version: '2.4'
 services:
   mysql:
-    image: "mysql/mysql-server:5.7.12"
+    image: "mysql/mysql-server:8.0.32"
     restart: always
     networks:
       - mm-test
@@ -19,7 +19,7 @@ services:
     volumes:
       - ./docker/mysql.conf.d/source.cnf:/etc/mysql/conf.d/mysql.cnf
   mysql-read-replica:
-    image: "mysql/mysql-server:5.7.12"
+    image: "mysql/mysql-server:8.0.32"
     restart: always
     networks:
       - mm-test

server/build/docker/mysql.conf.d/custom.cnf

@@ -1,6 +1,7 @@
 [mysqld]
 bind-address = 0.0.0.0
 
+default-authentication-plugin=mysql_native_password
 log-output = NONE
 slow-query-log = 0
 innodb_flush_log_at_trx_commit = 2

server/build/dotenv/migration.env

@@ -6,11 +6,11 @@ MYSQL_USERNAME=root
 MYSQL_PASSWORD=mostest
 MYSQL_SCHEMA=mattermost_test
 POSTGRES_MIGRATIONS_PATH=./channels/db/migrations/postgres
-MYSQL_DSN=${MYSQL_USERNAME}:${MYSQL_PASSWORD}@tcp(mysql:3306)/${MYSQL_SCHEMA}?charset=utf8mb4,utf8&readTimeout=30s&writeTimeout=30s&multiStatements=true
+MYSQL_DSN=${MYSQL_USERNAME}:${MYSQL_PASSWORD}@tcp(mysql:3306)/${MYSQL_SCHEMA}?charset=utf8mb4&readTimeout=30s&writeTimeout=30s&multiStatements=true
 POSTGRES_DSN=postgres://${PG_USERNAME}:${PG_PASSWORD}@postgres:5432/${PG_SCHEMA}?sslmode=disable
 
 MM_SERVICESETTINGS_ENABLELOCALMODE=true
 MM_SQLSETTINGS_DRIVERNAME=mysql
-MM_SQLSETTINGS_DATASOURCE=mmuser:mostest@tcp(mysql:3306)/mattermost_test?charset=utf8mb4,utf8&readTimeout=30s&writeTimeout=30s&multiStatements=true&maxAllowedPacket=4194304
+MM_SQLSETTINGS_DATASOURCE=mmuser:mostest@tcp(mysql:3306)/mattermost_test?charset=utf8mb4&readTimeout=30s&writeTimeout=30s&multiStatements=true&maxAllowedPacket=4194304
 MAX_WAIT_SECONDS=500
 IS_CI=true

server/build/dotenv/test.env

@@ -1,4 +1,4 @@
-TEST_DATABASE_MYSQL_DSN=mmuser:mostest@tcp(mysql:3306)/mattermost_test?charset=utf8mb4,utf8&readTimeout=30s&writeTimeout=30s&multiStatements=true&maxAllowedPacket=4194304
+TEST_DATABASE_MYSQL_DSN=mmuser:mostest@tcp(mysql:3306)/mattermost_test?charset=utf8mb4&readTimeout=30s&writeTimeout=30s&multiStatements=true&maxAllowedPacket=4194304
 TEST_DATABASE_POSTGRESQL_DSN=postgres://mmuser:mostest@postgres:5432/mattermost_test?sslmode=disable&connect_timeout=10
 TEST_DATABASE_MYSQL_ROOT_PASSWD=mostest
 GOBIN=/mattermost/server/bin

server/build/gitlab-dc.mysql.yml

@@ -1,7 +1,7 @@
 version: '2.4'
 services:
   mysql:
-    image: mattermostdevelopment/mirrored-mysql:5.7.12
+    image: mattermostdevelopment/mirrored-mysql:8.0.32
     restart: always
     environment:
       MYSQL_ROOT_HOST: "%"

server/build/gitlab-dc.schemamysql.yml

@@ -1,7 +1,7 @@
 version: '2.4'
 services:
   mysql:
-    image: mattermostdevelopment/mirrored-mysql:5.7.12
+    image: mattermostdevelopment/mirrored-mysql:8.0.32
     restart: always
     environment:
       MYSQL_ROOT_HOST: "%"