IntelliJ can shorten the classpath to a single classpath.jar in order to
circumvent errors originating from a too long classpath. This breaks the
filtering inside ModifiedClassPathRunner as the classpath contains only a
single jar to match against. This can be fixed by applying a similar
mechanism already provided for Surefire manifest-only booter JARs, which
extracts the real classpath from the JAR's Manifest file.

See gh-12535