Based on the message from artur.wawrzynkiewicz@ibexa.co :

Czesc Adam,
aktiualnie my nie morzemy installowac instancje w acceleratorze v4.6.1. Ja i Kamil zerknelismy dlaczego i problem sa aktualne dependecies.Accelerator builds are failing again. I have analyzed the core issue and found that the builds use outdated packages.
We have now Ibexa v4.6.1 tagged, the installer used following:

ibexa/prototype-automated-translation v4.0.5 Ibexa Prototype Automated Translation configuration ibexa/prototype-base v4.6.0 Ibexa Prototype Base ibexa/prototype-cli-tools v4.0.3 Ibexa Prototype CLI Tools ibexa/prototype-commerce v4.4.0 Ibexa Prototype Commerce Package ibexa/prototype-complex-workflow v4.0.2 Ibexa Prototype Complex Workflow ibexa/prototype-content-pharma -> v4.2.3 Ibexa Prototype Content Package - Pharma ibexa/prototype-content-structure -> v4.2.2 Ibexa Prototype Content Structure ibexa/prototype-dam-unsplash v4.6.0 Ibexa Prototype DAM Unsplash Connector configuration ibexa/prototype-design-base v4.6.0 Ibexa Prototype Design Base Bundle ibexa/prototype-design-creamy v4.6.0 Ibexa Prototype Design Creamy Bundle ibexa/prototype-design-creamy-commerce v4.6.0 Ibexa Prototype Design Creamy Commerce Bundle ibexa/prototype-experience v4.6.0 Ibexa Prototype Experience Package ibexa/prototype-language-english v4.6.0 Ibexa Prototype Language Package for english ibexa/prototype-language-german v4.6.1 Ibexa Prototype Language Package - German ibexa/prototype-migrations v4.6.0 Ibexa Prototype Migrations Package ibexa/prototype-page v4.6.0 Ibexa Prototype Page Bundle ibexa/prototype-site-factory v4.6.0 Ibexa Prototype Site Factory  

Especially content-structure v4.2.2 causes the issue but we do have it tagged with v4.6.0 and in the Use Case commerce_46 it should pick the latest is defined.
content-structure & content-pharma require ibexa/connector-qualifio and ibexa/connector-seenthis packages. Both these packages have dependency on symfony/event-dispatcher-contracts set to ^2.2 (https://github.com/ibexa/connector-qualifio/blob/v4.6.1/composer.json#L22 & https://github.com/ibexa/connector-seenthis/blob/v4.6.1/composer.json#L22) but ibexa/commerce-skeleton has it locked on ^3.4 (https://github.com/ibexa/commerce-skeleton/blob/v4.6.1/composer.lock#L15264) Could you pass it to Adam / Engineering so they can have a look? I will be for the whole day offline on the plane commerce-skeleton for 4.6.0: https://github.com/ibexa/commerce-skeleton/blob/v4.6.0/composer.lock#L15297

 
We should remove all dependencies on symfony/event-dispatcher-contracts. We have already did it for all required packages but we missed optional packages like connector-qualifio.