Avoid Python re-installation if already installed

This saves 8 minutes from build-image command

Signed-off-by: Hanwen <[email protected]>

Author: hanwen-cluster

cookbooks/aws-parallelcluster-shared/resources/install_pyenv.rb

@@ -53,5 +53,6 @@
     make
     make install
     VENV
+    not_if { Dir.glob("#{prefix}/versions/#{python_version}/bin/python*").any? }
   end
 end