clang-format: show required version in skip message

This will help people to configure their black

Differential Revision: https://phab.mercurial-scm.org/D9890

tests/hghave.py

@@ -591,7 +591,7 b' def has_pylint():'
     return matchoutput("pylint --help", br"Usage:[ ]+pylint", True)
 
 
-@check("clang-format", "clang-format C code formatter")
+@check("clang-format", "clang-format C code formatter (>= 11)")
 def has_clang_format():
     m = matchoutput('clang-format --version', br'clang-format version (\d+)')
     # style changed somewhere between 10.x and 11.x