Update collations

Update the table collations to remove this warning.

```
'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
'utf8mb3_unicode_ci' is a collation of the deprecated character set UTF8MB3. Please consider using UTF8MB4 with an appropriate collation instead.
```