fix(migrations): Restore type definitions for API class used in apps

[nickvergessen]

• refactor(psalm): Modernize migration doc #58282 broke typing in apps, because the subclass SimpleMigrationStep that is used in all apps now has no Closure typing anymore.

Before

ERROR: MoreSpecificImplementedParamType - lib/Migration/Version23000Date20260107162758.php:30:56 - Argument 2 of OCA\Talk\Migration\Version23000Date20260107162758::changeSchema has the more specific type 'Closure():OCP\DB\ISchemaWrapper', expecting 'Closure' as defined by OCP\Migration\SimpleMigrationStep::changeSchema (see https://psalm.dev/140)
	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {

Option1 (bad) - Remove docs in Talk

Before removing Talk docs	After
Types are hinted and parameter name of createTable is known	Types are lost, no hinting

Option2 (better) - Restore the docs on SimpleMigrationStep

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       No errors found!       
                              
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Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

[szaimen]

🐘