[Fix #9770] Update Lint/EmptyBlock to handle procs the same way as lambdas

[dvandersluis]

Lint/EmptyBlock now treats procs the same way as lambdas (governed by the AllowLambdas configuration).

Fixes #9770.

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[dvandersluis]

@bbatsov it'd probably be "better" to replace the AllowLambdas configuration with AllowLambdasAndProcs or something, but this would break existing configurations. I was thinking about deprecating AllowLambdas with a warning (like we did in #9098) but it's probably "good enough" to just overload the configuration.

If you want me to change it, let me know.

[koic]

it's probably "good enough" to just overload the configuration.

I agree with this opinion. It seems better to me to update the AllowEmptyLambdas configuration.

[bbatsov]

The change is fine in it's current form. Thanks!