[ external : spring ] - Compilation with Kotlin compile daemon was not successful

jdk11: https://ci.adoptopenjdk.net/view/work-in-progress/job/grinder_sandbox_new/613/consoleFull

```
Compilation with Kotlin compile daemon was not successful
18:24:15 java.lang.NullPointerException
18:24:15 at org.jetbrains.kotlin.incremental.IncrementalModuleEntry.hashCode(IncrementalModuleInfo.kt)
18:24:15 at java.base/java.util.HashMap.hash(HashMap.java:340)
...
...
19:56:11 Found test failures in 1 test task:
19:56:11
19:56:11 :spring-boot-project:spring-boot-tools:spring-boot-gradle-plugin:test
19:56:11 org.springframework.boot.gradle.tasks.run.BootRunIntegrationTests > applicationPluginJvmArgumentsAreUsed()[10]
...
19:56:11 org.springframework.boot.gradle.tasks.run.BootRunIntegrationTests > defaultJvmArgs()[10]
...
19:56:11
19:56:11 FAILURE: Build failed with an exception.
```

jdk8: https://ci.adoptopenjdk.net/view/work-in-progress/job/grinder_sandbox_new/612/consoleFull

```
16:28:31 Compilation with Kotlin compile daemon was not successful
16:28:31 java.lang.NullPointerException
16:28:31 at org.jetbrains.kotlin.incremental.IncrementalModuleEntry.hashCode(IncrementalModuleInfo.kt)

...
...
18:14:12 FAILURE: Build completed with 2 failures.
18:14:12
18:14:12 1: Task failed with an exception.
18:14:12 -----------
18:14:12 * What went wrong:
18:14:12 Execution failed for task ':spring-boot-project:spring-boot-autoconfigure:test'.
18:14:12 > Process 'Gradle Test Executor 6' finished with non-zero exit value 137
18:14:12 This problem might be caused by incorrect test process configuration.
18:14:12 Please refer to the test execution section in the User Manual at https://docs.gradle.org/6.9.2/userguide/java_testing.html#sec:test_execution
18:14:12
18:14:12 * Try:
18:14:12 Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
18:14:12 ==============================================================================
18:14:12
18:14:12 2: Task failed with an exception.
18:14:12 -----------
18:14:12 * What went wrong:
18:14:12 Execution failed for task ':spring-boot-project:spring-boot-tools:spring-boot-gradle-plugin:test'.
18:14:12 > There were failing tests. See the report at: file:///spring-boot/spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/build/reports/tests/test/index.html

```

Start with the linked JDK 8 and JDK 11 CI console logs, then reproduce the failing Gradle tasks named in the report: spring-boot-autoconfigure:test and spring-boot-gradle-plugin:test. Inspect BootRunIntegrationTests and the Kotlin compile-daemon failure; done means the compilation completes without the NullPointerException and the reported tests pass.

Written by the indexing model from the issue text.