Move a verbose line of %pyproject_buildrequires from stdout to stderr
    
    The `rm -v` command prints the output to stderr, polluting the generated buildrequires
    
      $ rm -rfv pytest_harvest.dist-info/
      removed 'pytest_harvest.dist-info/METADATA'
      removed 'pytest_harvest.dist-info/LICENSE'
      removed 'pytest_harvest.dist-info/top_level.txt'
      removed 'pytest_harvest.dist-info/entry_points.txt'
      removed directory 'pytest_harvest.dist-info/'
    
    This can lead to RPM errors:
    
      error: Dependency tokens must begin with alpha-numeric, '_' or '/': 'pytest_harvest.dist-info/METADATA'
    
    Or bogus dependencies -- the SRPM requires "removed" and "directory".
    
    See https://github.com/rpm-software-management/rpm/pull/889