ScrutinizerCI - auto start build when dependent packages are updated?

Question

PHP

Greetings, comrades!
There is no answer to the question from the topic, maybe someone came across?
In more detail, we have the following situation - we have 2 composer packages "A" and "B", ("A" is dependent on "B"), registered on packagist.org, and "connected" to each ScrutinizerCI, which runs their builds (unit tests) on different environments when pushing, PR, MR, and so on to the turnip.
Everything works, but one feature is missing - I would really like that when updating package "A" (which, I remind you, is a dependency of package "B"), the assembly of not only package "A", but also "B" was automatically launched, to make sure that we didn't break anything. Moreover, the build should start with a slight delay, since packagist.org does not immediately "pull up" the information that package "A" has been updated, but with some delay.
I looked in webhooks - there is just a hook on the URI " https://scrutinizer-ci.com/github-callback " without any separate identifier (github itself generates the sent data), so it will not work to hang a new hook for turnip "A" .
How can you win this case, do you know?