Bluetooth: host: test: remove adv/resume2

I am the original author of the test that is being removed. The test was
added in https://github.com/zephyrproject-rtos/zephyr/pull/70670

 to try
to specify the behavior of automatic advertiser resuming in the Host.

It turns out now that the behavior of this feature depends on which
Controller is in use and can fail incorrectly.

The test assumes the DUT will be able to create `CONFIG_BT_MAX_CONN`
peripheral connections. But this is not necessarily true. E.g. Some
Controllers, like the SoftDevice Controller, may reserve some Host
connection slots for central roles, making the max number of peripheral
connections smaller.

In conclusion, the test is not correct and should be removed.

Signed-off-by: Aleksander Wasaznik <aleksander.wasaznik@nordicsemi.no>