Remove old app test script path
Remove old app test script path

Now that https://github.com/matrix-org/pipelines/pull/112 has merged, we no
longer need to support this old path for launching app-level tests.

matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk