Acknowledge click 8.0 incompatibility (ansible#3001)

Upcoming changes in click break click-help-colors plugin so we need to prevent breaking at runtime until upstream issues are sorted.

Related: click-contrib/click-help-colors#12
Related: pallets/click#1721

setup.cfg

@@ -67,7 +67,7 @@ setup_requires =
 # These are required in actual runtime:
 install_requires =
     cerberus >= 1.3.1
-    click >= 7.0
+    click >= 7.0, < 8.0  # https://github.com/click-contrib/click-help-colors/issues/12
     click-completion >= 0.5.1
     click-help-colors >= 0.6
     cookiecutter >= 1.6.0, != 1.7.1