Disable ContextCustomizer implementations that only impacts the BeanRegistry in an AOT-optimized context

[snicoll]

Running a WebMvcTest in a native image fails with

Failures (1):
  JUnit Jupiter:DemoControllerTests
    ClassSource [className = 'com.example.demo.DemoControllerTests', filePosition = null]
    => java.lang.IllegalStateException: Unable to instantiate DeterminableImportSelector org.springframework.boot.autoconfigure.ImportAutoConfigurationImportSelector
       org.springframework.boot.test.context.ImportsContextCustomizer$ContextCustomizerKey.instantiate(ImportsContextCustomizer.java:316)
       org.springframework.boot.test.context.ImportsContextCustomizer$ContextCustomizerKey.determineImports(ImportsContextCustomizer.java:296)
       org.springframework.boot.test.context.ImportsContextCustomizer$ContextCustomizerKey.determineImports(ImportsContextCustomizer.java:276)
       org.springframework.boot.test.context.ImportsContextCustomizer$ContextCustomizerKey.<init>(ImportsContextCustomizer.java:236)
       org.springframework.boot.test.context.ImportsContextCustomizer.<init>(ImportsContextCustomizer.java:71)
       [...]
     Caused by: java.lang.NoSuchMethodException: org.springframework.boot.autoconfigure.ImportAutoConfigurationImportSelector.<init>()
       java.lang.Class.getConstructor0(DynamicHub.java:3585)
       java.lang.Class.getDeclaredConstructor(DynamicHub.java:2754)
       org.springframework.boot.test.context.ImportsContextCustomizer$ContextCustomizerKey.instantiate(ImportsContextCustomizer.java:311)
       [...]

This can be reproduced using this sample. This code seems to be required to build a suitable MergedContextConfiguration but I wonder if it should be running at all since the context has already been fully prepared at this point. See also #32420

[snicoll]

A note that Spring Native has an hard-coded list of ContextCustomizer implementations to ignore at runtime:

private static final Predicate<SpringFactory> CONTEXT_CUSTOMIZER_FACTORY = factoryEntry(
			"org.springframework.test.context.ContextCustomizerFactory",
			"org.springframework.boot.test.autoconfigure.OverrideAutoConfigurationContextCustomizerFactory",
			"org.springframework.boot.test.autoconfigure.filter.TypeExcludeFiltersContextCustomizerFactory",
			"org.springframework.boot.test.context.ImportsContextCustomizerFactory");

[snicoll]

So it turns out that disabling the 3 implementations above were enough to fix the sample. It's a good first step in the right direction but we should be discussing how to make that a bit more declarative/obvious. This should be addressed by #32262