Await async handle_trap function in bgp trap tests

[johannaengland]

Scope and purpose

I noticed that when running the testsuite I got the following pytest warnings:

tests/trapobservers/bgp_traps_test.py::TestBgpTrapObserver::test_when_trap_is_missing_required_varbinds_it_should_do_nothing
  /home/johanna/zino/tests/trapobservers/bgp_traps_test.py:34: RuntimeWarning: coroutine 'BgpTrapObserver.handle_trap' was never awaited
    observer.handle_trap(trap=backward_transition_trap)
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

tests/trapobservers/bgp_traps_test.py::TestBgpTrapObserver::test_when_trap_has_invalid_remote_addr_it_should_do_nothing
  /home/johanna/zino/tests/trapobservers/bgp_traps_test.py:45: RuntimeWarning: coroutine 'BgpTrapObserver.handle_trap' was never awaited
    observer.handle_trap(trap=backward_transition_trap)
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

tests/trapobservers/bgp_traps_test.py::TestBgpTrapObserver::test_when_trap_has_invalid_oper_state_it_should_do_nothing
  /home/johanna/zino/tests/trapobservers/bgp_traps_test.py:56: RuntimeWarning: coroutine 'BgpTrapObserver.handle_trap' was never awaited
    observer.handle_trap(trap=backward_transition_trap)
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

This removes these warning by actually awaiting the async handle_trap function and marking the tests as async themselves.

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• Added a changelog fragment for towncrier
  • this does not change any behavior, only corrects the way tests are run
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  • well, the tests are what is changed
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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.45%. Comparing base (395ac8e) to head (712a09d).
Report is 63 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #323      +/-   ##
==========================================
+ Coverage   97.32%   97.45%   +0.13%     
==========================================
  Files          64       64              
  Lines        7919     7919              
==========================================
+ Hits         7707     7717      +10     
+ Misses        212      202      -10     

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