Wildcarding json keys in json query

PG 11.5 on linux

Let's say I store a jsonb in a column called test_results that looks like
this...

{
ports : {
port_abc:{min: 5, max: 7, mean: 6},
port_def:{min: 5, max: 9, mean: 7},
port_ghi:{min: 6, max: 10, mean: 8}
}
}

And I want to to get all the port names where the mean is >= 7.

This works...

select 1 from mytbl where cast(test_results#>'{ports,*port_abc*,mean}' as
float) >= 7 ;

But I want *all *the ports that have mean >= 7.
Something akin to...

select 1 from mytbl where cast(test_results#>'{ports,***,mean}' as float)
>= 7 ;

But the "*" doesn't work :-(

Any ideas ?
Thanks!