Dependent PR's/Issues automation

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**Discussion**
So the last thing that will make our life easier is to label PR's or issues with a dependent label. This tool will help us manage the PR's and issues better.
https://github.com/marketplace/actions/dependent-issues
https://github.com/Levi-Lesches/blocking-issues
When PR X is dependent on PR Y. We'll mark it that is dependent on that issue. PR X will be blocked from being merged. After PR X is merged u the blockade will be removed. This also supports cross-repository dependencies.

A few example PR's that are dependent on other PR's
https://github.com/FreeTubeApp/FreeTube/pull/1819
https://github.com/FreeTubeApp/FreeTube/pull/1568
https://github.com/FreeTubeApp/FreeTube/pull/1456

We ofcourse can also do this with issues. Issue X will get blocked because issue Y needs to be taken care of first. I saw it allot in the repo.

I promise that this is the last of my automation madness :)