[Misc] Add missing license headers

[comaniac]

Due to out of order merge #11330

cc @DarkLight1337 @mgoin @russellb @simon-mo

[github-actions]

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[russellb]

lgtm

[russellb]

This is also fixed by #12694

[comaniac]

I see. Then we should just merge that one ASAP and close this one.