Workaround crossgen2/ilasm CI test pass incompatibility (#56572)

Workaround crossgen2/ilasm CI test pass incompatibility (#56572)

- The scripts for running crossgen on the app are incompatible with the ilasm/ildasm scripts
- We don't have many of these tests, and they don't test many interesting details for ilasm/ildasm
- Simply disable these tests in the ILasm/ildasm test passes

Fixes #56484

Also, a small drive by fix to not attempt to compile the composite-r2r image. This makes it simple to force the test to re-run crossgen2 by just deleting the IL-CG2 subdirectory of the test