FlowTest is flaky

https://github.com/bumptech/glide/actions/runs/4408020773/jobs/7722477907

```

com.bumptech.glide.integration.ktx.FlowsTest > flow_onClose_clearsTarget FAILED
expected not to be: null
at com.bumptech.glide.integration.ktx.FlowsTest$flow_onClose_clearsTarget$1.invokeSuspend(FlowsTest.kt:335)
at app//kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:104)
at kotlinx.coroutines.test.TestDispatcher.processEvent$kotlinx_coroutines_test(TestDispatcher.kt:28)
at kotlinx.coroutines.test.TestCoroutineScheduler.tryRunNextTaskUnless$kotlinx_coroutines_test(TestCoroutineScheduler.kt:100)
at kotlinx.coroutines.test.TestCoroutineScheduler.advanceUntilIdleOr$kotlinx_coroutines_test(TestCoroutineScheduler.kt:120)
at kotlinx.coroutines.test.TestCoroutineScheduler.advanceUntilIdle(TestCoroutineScheduler.kt:113)
at kotlinx.coroutines.test.TestBuildersKt__TestBuildersKt.runTestCoroutine(TestBuilders.kt:237)
at kotlinx.coroutines.test.TestBuildersKt.runTestCoroutine(Unknown Source)
at kotlinx.coroutines.test.TestBuildersKt__TestBuildersKt$runTestCoroutine$1.invokeSuspend(TestBuilders.kt)
at app//kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
at kotlinx.coroutines.EventLoopImplBase.processNextEvent(EventLoop.common.kt:284)
at kotlinx.coroutines.BlockingCoroutine.joinBlocking(Builders.kt:85)
at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking(Builders.kt:59)
at kotlinx.coroutines.BuildersKt.runBlocking(Unknown Source)
at kotlinx.coroutines.BuildersKt__BuildersKt.runBlocking$default(Builders.kt:38)
at kotlinx.coroutines.BuildersKt.runBlocking$default(Unknown Source)
at kotlinx.coroutines.test.TestBuildersJvmKt.createTestResult(TestBuildersJvm.kt:12)
at kotlinx.coroutines.test.TestBuildersKt__TestBuildersKt.runTest(TestBuilders.kt:166)
at kotlinx.coroutines.test.TestBuildersKt.runTest(Unknown Source)
at kotlinx.coroutines.test.TestBuildersKt__TestBuildersKt.runTest(TestBuilders.kt:154)
at kotlinx.coroutines.test.TestBuildersKt.runTest(Unknown Source)
at kotlinx.coroutines.test.TestBuildersKt__TestBuildersKt.runTest$default(TestBuilders.kt:147)
at kotlinx.coroutines.test.TestBuildersKt.runTest$default(Unknown Source)
at com.bumptech.glide.integration.ktx.FlowsTest.flow_onClose_clearsTarget(FlowsTest.kt:304)

```

Start with the linked GitHub Actions run and inspect the failing flow_onClose_clearsTarget test in FlowsTest.kt, especially lines 304 and 335. Reproduce the failure and determine why the target is still null; done means the test reliably passes without introducing another flaky behavior.

Written by the indexing model from the issue text.