dependency fix for python3 (#18118)

* dependency fix for python3

* version cleanup

Co-authored-by: Marc Mengel <mengel@fnal.gov>

var/spack/repos/builtin/packages/py-cheroot/package.py

@@ -11,15 +11,16 @@ class PyCheroot(PythonPackage):
     """ Highly-optimized, pure-python HTTP server """
 
     homepage = "https://cheroot.cherrypy.org/"
-    url      = "https://pypi.io/packages/source/c/cheroot/cheroot-6.5.5.tar.gz"
+    url = "https://pypi.io/packages/source/c/cheroot/cheroot-6.5.5.tar.gz"
 
-    version(
-        '6.5.5', sha256='f6a85e005adb5bc5f3a92b998ff0e48795d4d98a0fbb7edde47a7513d4100601')
+    version('8.3.0', sha256='a0577e1f28661727d472671a7cc4e0c12ea0cbc5220265e70f00a8b8cb628931')
+    version('6.5.5', sha256='f6a85e005adb5bc5f3a92b998ff0e48795d4d98a0fbb7edde47a7513d4100601')
 
     depends_on('py-setuptools', type='build')
     depends_on('py-setuptools-scm@1.15.0:', type='build')
     depends_on('py-setuptools-scm-git-archive@1.0:', type='build')
     depends_on('py-more-itertools@2.6:', type=('build', 'run'))
     depends_on('py-six@1.11.0:', type=('build', 'run'))
-    depends_on('py-backports-functools-lru-cache', type=('build', 'run'))
+    depends_on('py-backports-functools-lru-cache', type=('build', 'run'),
+               when='^python@:3.3')
     depends_on('python@2.7:2.8,3.4:', type=('build', 'run'))