OEmbed Media Source and related controller use LoggerChannelInterface in their constructors which is not compatible with the monolog module

Looks good to me, the interface of LoggerChannelInterface says:

 * This interface defines the full behavior of the central Drupal logger
 * facility. However, when writing code that does logging, use the generic
 * \Psr\Log\LoggerInterface for typehinting instead (you shouldn't need the
 * methods here).

So I can't see any issues with changing this. Will see what the testbot says. Not exactly sure if testing this makes sense, I suppose we could use a different logger in the oembed tests, but haven't seen any examples of that done elsewhere.

I am wondering whether something like this could be automatically checked.

Otherwise, totally +1

I think best thing to do will be to add a follow-up task to mark the LoggerChannelInterface @internal. So at least IDEs will help us. This task should also replace other incorrect typehints.

Also how does this break the monolog module? I don't think this is true since #2749859: Logger channel factory must return instances of LoggerChannelInterface.

But there is no harm in obeying the instructions not to use it that exist on the interface. As an API widening (not change) I don't think this needs tests.

Committed and pushed e6a096cf45 to 8.7.x and faf551f882 to 8.6.x. Thanks!