tests/gnrc_ipv6_nib: rtr_ltime test

[xnumad]

Contribution description

This PR only provides a test to verify that _handle_rtr_timeout does not have any effect on any RA options:

The Router Lifetime applies only to
the router's usefulness as a default router; it
does not apply to information contained in other
message fields or options. Options that need time
limits for their information include their own
lifetime fields.

• https://datatracker.ietf.org/doc/html/rfc4861

Emphasis added to highlight what part exactly this test covers. (In particular, it does not cover testing that the "Router Lifetime" has any effect to "the router's usefulness as a default router".)

Test is implemented as part of the "base test function", causing 4 tests to fail if not providing an implementation.

Issues/PRs references

Test is fulfilled by #20329 and #20371 (alone each, but they are also not mutually exclusive).
While #20329 itself already provides tests, this PR is an additional test (so no duplicate tests across PRs or sth). (In fact, they do not seem to cover the code of that PR; they still succeed if only keeping the tests from the PR.)

[riot-ci]

Murdock results

✔️ PASSED

e767e44 tests/gnrc_ipv6_nib: refactor: extract DAD test

Success	Failures	Total	Runtime
63	0	63	01m:31s

Artifacts

• Documentation preview

[xnumad]

Rebased, meaning PR can now be merged since test does not fail anymore since the code being tested was fixed (through merge of https://github.com/RIOT-OS/RIOT/pull/20329/files#diff-fba26fd610698922256809a70531c3b18dc624a771563ea8887a08bbf762c457L1470-L1471)

[xnumad]

Force push: Modified commit: Adjusted for changes meanwhile made to master (via bb9ca2e)

[fabian18]

Could you factor this out to a new function, please?
And then not call this inside test_handle_pkt__rtr_adv__options_success().
Effectively it is testing if Duplicate Address Detection is triggered by SLAAC.

[xnumad]

Yes. I thought since SLAAC is triggered by the Prefix Information Option in the Router Advertisement, I could leave its DAD test there. But your suggestion makes test_handle_pkt__rtr_adv__options_success() idempotent, which can be helpful.

[fabian18]

make -C tests/net/gnrc_ipv6_nib flash term

OK (53 tests)
{ "threads": [{ "name": "idle", "stack_size": 8192, "stack_used": 436}]}
{ "threads": [{ "name": "main", "stack_size": 12288, "stack_used": 2564}]}