The php docs are not very clear about that one.

This return type is conditional to $params['wrapperClass']. Luckily,
recent versions of Psalm allow documenting it properly.
See https://github.com/vimeo/psalm/issues/3277

Note that phpstan is not able to understand this yet, but still attempts
to, hence the extra ignore rules.

1. `FetchMode::STANDARD_OBJECT` and `FetchMode::CUSTOM_OBJECT` are no longer supported.
2. `FetchMode::COLUMN` with a non-zero index is no longer supported.
3. Incompatible change in the `Connection::fetchColumn()` signature where the 3rd argument is now `$types`, not `$columnIndex`.

Reworked type-based and conditions and clarified some types to justify the ones that remain unchanged.

The `PostgreSqlPlatform`, `SQLAnywherePlatform` and `SQLServerPlatform` classes have been renamed to `PostgreSQL94Platform`, `SQLAnywhere16Platform` and `SQLServer2012Platform` respectively.

When deprecating an old platform version, we can deprecate and later remove a specific class. Otherwise, there's no way to express the deprecation on the class level and the upgrade notes contain sentences like: "`XYZPlatform` and `XYZKeywords` now represent XYZ (version)".