Move to temporary directory before running dev-build test (#17028)
Move to temporary directory before running dev-build test (#17028)

Without this the test would leave spurious "spack-build-*.txt"
files in the current working directory.
iulian787/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,iulian787/spack,LLNL/spack,LLNL/spack,iulian787/spack,LLNL/spack