Previously, the .class file for the renamed properties class was
on the class path of the compilation in two places:
1. The output directory of the test's previous compilation
2. The output directory of the compilation of src/test/java of
spring-boot-configuration-processor
The first of these locations is addressed by updating TestProject.
The .class file is now deleted from the project's output location
at the same time as the .java file is deleted from its source
location.
The second of these locations is addressed by configuring the class
path of the compiler to include a copy of the result of compiling
src/test/java of spring-boot-configuration-processor. From this copy
entries can then be deleted as needed without destabilizing other tests.
Closes gh-26271
94e810201e