Fix flaky unit test

[MrSerth]

• Failed: https://github.com/openHPI/poseidon/actions/runs/10672500728/job/29580106040?pr=658#step:5:866
• Successful: https://github.com/openHPI/poseidon/actions/runs/10672500728/job/29580183775

=== RUN   TestInactivityTimerTestSuite/TestTimerIsNotResetAfterDeadline
time="2024-09-02T20:08:08.997039Z" level=info msg="Returning runner due to inactivity timeout" package=runner runner_id=0-MY-DEFAULT-RANDOM-UUID
    inactivity_timer_test.go:84: 
        	Error Trace:	/home/runner/work/poseidon/poseidon/internal/runner/inactivity_timer_test.go:84
        	Error:      	Should be false
        	Test:       	TestInactivityTimerTestSuite/TestTimerIsNotResetAfterDeadline
--- FAIL: TestInactivityTimerTestSuite (3.14s)
    --- PASS: TestInactivityTimerTestSuite/TestResetTimeoutExtendsTheDeadline (0.38s)
    --- PASS: TestInactivityTimerTestSuite/TestRunnerIsNotReturnedBeforeTimeout (0.25s)
    --- PASS: TestInactivityTimerTestSuite/TestRunnerIsReturnedAfterTimeout (0.30s)
    --- PASS: TestInactivityTimerTestSuite/TestSetupTimeoutStopsOldTimeout (0.50s)
    --- PASS: TestInactivityTimerTestSuite/TestStopTimeoutStopsTimeout (0.40s)
    --- PASS: TestInactivityTimerTestSuite/TestTimeoutPassedReturnsFalseBeforeDeadline (0.20s)
    --- PASS: TestInactivityTimerTestSuite/TestTimeoutPassedReturnsTrueAfterDeadline (0.40s)
    --- PASS: TestInactivityTimerTestSuite/TestTimerIsInactiveWhenDurationIsZero (0.30s)
    --- FAIL: TestInactivityTimerTestSuite/TestTimerIsNotResetAfterDeadline (0.40s)

• Failed: https://github.com/openHPI/poseidon/actions/runs/10672601360/job/29580373687?pr=662
• Successful: https://github.com/openHPI/poseidon/actions/runs/10672601360/job/29580442933

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10672760544/job/29580781602?pr=668
• Failed 2: https://github.com/openHPI/poseidon/actions/runs/10672760544/job/29580843003
• Failed 3: https://github.com/openHPI/poseidon/actions/runs/10672760544/job/29580919548
• Failed 4: https://github.com/openHPI/poseidon/actions/runs/10672760544/job/29580979586
• Successful: https://github.com/openHPI/poseidon/actions/runs/10672760544/job/29581035965

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10672757995/job/29580775156
• Successful: https://github.com/openHPI/poseidon/actions/runs/10672757995/job/29580930062

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10672909118/job/29581172903
• Successful: https://github.com/openHPI/poseidon/actions/runs/10672909118/job/29581224469

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10672981021/job/29581370164?pr=665
• Successful: https://github.com/openHPI/poseidon/actions/runs/10672981021/job/29581424602

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10679753041/job/29599985911?pr=667
• Successful: https://github.com/openHPI/poseidon/actions/runs/10679753041/job/29602811606

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10681315147/job/29604707683
• Successful: https://github.com/openHPI/poseidon/actions/runs/10681315147/job/29605564049

same error as above

• Failed: https://github.com/openHPI/poseidon/actions/runs/10682020244/job/29606923642?pr=660
• Failed 2: https://github.com/openHPI/poseidon/actions/runs/10682020244/job/29607516951
• Failed 3: https://github.com/openHPI/poseidon/actions/runs/10682020244/job/29607925108
• Failed 4: https://github.com/openHPI/poseidon/actions/runs/10682020244/job/29608254434
• Successful: https://github.com/openHPI/poseidon/actions/runs/10682020244/job/29608367521

same error as above