Upgrade Gradle to 7.1.1

[TobiGr]

• I carefully read the contribution guidelines and agree to them.
• I have tested the API against NewPipe.
• I agree to create a pull request for NewPipe as soon as possible to make it compatible with the changed API.

Upgrade Gradle to 7.1.1

Closes TeamNewPipe/NewPipe#6651

Todo:

• check if anything broke
• Go though upgrade guide and check deprecations / API changes

[litetex]

LGTM

Can this be switched to "ready for reviewing" or are there any things speaking against it?

[TobiGr]

I did not have time to check the upgrade notes. Will do it later

[XiangRongLin]

@TacoTheDank do you have time to do this? since you already went through this process once, you should know what to look out for

[TacoTheDank]

@XiangRongLin Sorry for late reply. Sure, I'll look into it :) should I do a separate PR?

[TobiGr]

@TacoTheDank Feel free to do so

[TacoTheDank]

@TobiGr this can be closed, I believe

[TobiGr]

thanks