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>

.github/workflows/esrupgrade-common.yml

@@ -60,7 +60,7 @@ jobs:
             --ulimit nofile=8096:8096 \
             --env-file=dotenv/test.env \
             --env MM_SQLSETTINGS_DRIVERNAME="mysql" \
-            --env MM_SQLSETTINGS_DATASOURCE="mmuser:mostest@tcp(mysql:3306)/mattermost_test?charset=utf8mb4,utf8&multiStatements=true&maxAllowedPacket=4194304" \
+            --env MM_SQLSETTINGS_DATASOURCE="mmuser:mostest@tcp(mysql:3306)/mattermost_test?charset=utf8mb4&multiStatements=true&maxAllowedPacket=4194304" \
             -v ~/work/mattermost:/mm \
             -w /mm \
             $BUILD_IMAGE &