Create script to create generic type annotations for EntityRepository

[shopwareBot]

With [https://shopware.atlassian.net/browse/NEXT-22942|https://shopware.atlassian.net/browse/NEXT-22942] we introduced generic type templates to

{{\Shopware\Core\Framework\DataAbstractionLayer\EntityRepository}}

{{\Shopware\Core\System\SalesChannel\Entity\SalesChannelRepository}}

{{\Shopware\Core\Framework\DataAbstractionLayer\Search\EntitySearchResult}}

which resulted in many PHPStan errors. we have completely ignored them. this should be fixed by a script, which adds the generic type annotation to all occurrences of those classes

[shopwareBot]

[public] Shopware automated response: This issue is linked to the internal issue: NEXT-29041

[created from NEXT-29041, comment 533484]