It possible to start several test generation simultaneously, which may lead to errors

[tyuldashev]

Description

When generate tests for Python it's possible to start many generations at the same time. Quite often it leads to problems, for instance UTBot cannot clean up temp folders and fails with exception.

To Reproduce

Steps to reproduce the behavior:

1. Open some Python project
2. Start generation for some function
3. Don't wait till it's finished and start another one.

Expected behavior
Related item is disabled in the menu, it's not possible to invoke generation till first one finished.

Actual behavior

Second, third... generation could be started.

Visual proofs (screenshots, logs, images)

Exceptions:

java.io.FileNotFoundException: C:\Users\T00814~1\AppData\Local\Temp\UTBot\python-test-generation-86979363890496480421\148_run_sum.py (The system cannot find the path specified)
	at java.base/java.io.FileOutputStream.open0(Native Method)
	at java.base/java.io.FileOutputStream.open(FileOutputStream.java:293)
	at java.base/java.io.FileOutputStream.<init>(FileOutputStream.java:235)
	at java.base/java.io.FileOutputStream.<init>(FileOutputStream.java:184)
	at kotlin.io.FilesKt__FileReadWriteKt.writeBytes(FileReadWrite.kt:108)
	at kotlin.io.FilesKt__FileReadWriteKt.writeText(FileReadWrite.kt:134)
	at kotlin.io.FilesKt__FileReadWriteKt.writeText$default(FileReadWrite.kt:134)
	at org.utbot.python.utils.TemporaryFileManager.writeToAssignedFile(TemporaryFileManager.kt:27)
	at org.utbot.python.utils.TemporaryFileManager.createTemporaryFile(TemporaryFileManager.kt:39)
	at org.utbot.python.utils.TemporaryFileManager.createTemporaryFile$default(TemporaryFileManager.kt:32)
	at org.utbot.python.PythonEvaluationKt.startEvaluationProcess(PythonEvaluation.kt:79)
	at org.utbot.python.PythonEngine$fuzzing$1.invokeSuspend(PythonEngine.kt:161)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlin.sequences.SequenceBuilderIterator.hasNext(SequenceBuilder.kt:129)
	at org.utbot.python.PythonTestCaseGenerator.generate(PythonTestCaseGenerator.kt:185)
	at org.utbot.python.PythonTestGenerationProcessor.processTestGeneration(PythonTestGenerationProcessor.kt:100)
	at org.utbot.python.PythonTestGenerationProcessor.processTestGeneration$default(PythonTestGenerationProcessor.kt:34)
	at org.utbot.intellij.plugin.language.python.PythonDialogProcessor$createTests$1.run(PythonDialogProcessor.kt:135)
	at com.intellij.openapi.progress.impl.CoreProgressManager.startTask(CoreProgressManager.java:442)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.startTask(ProgressManagerImpl.java:114)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcessWithProgressAsynchronously$5(CoreProgressManager.java:493)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$3(ProgressRunner.java:252)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:188)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$12(CoreProgressManager.java:608)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:683)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:639)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:607)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:60)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:175)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$4(ProgressRunner.java:252)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:702)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:699)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:699)
	at java.base/java.lang.Thread.run(Thread.java:833)

Folders not deleted after generation finished:

Additional context

Please apply approach used in Java, there simultaneous generation is prohibited.