Include Agent key already in use warning message in expected E2E expected errors/warnings

[Rebits]

Description

It has been detected in #5397, that initial tests detect an unexpected warning in managers:

            "2024/05/17 18:12:03 wazuh-remoted: WARNING: Agent key already in use: agent ID '005'"

This warning is expected due to the logic of Vulnerability Detection E2E tests, were agents are removed before and after configuring the Vulnerability Detection module depending on the test case. This agent removal produces these expected warnings
We should include this warning in the expected error list.

Tasks

• Include Agent key already in use warning into the expected E2E errors list.

Validation

• E2E Vulnerability detection initial scans no longer detect this warning as unexpected.

[Rebits]

Currently testing among different E2E fixes. Check #5397 for more information

[Rebits]

Created custom branch to test all E2E fixes tmp-merge-fixes-E2E-tests

Build: https://ci.wazuh.info/job/Test_e2e_system/289/

[rafabailon]

LGTM