Install python 3.9 for al2

Author: hgreebe

cookbooks/aws-parallelcluster-shared/attributes/versions.rb

@@ -1,10 +1,8 @@
 # Python Version
 default['cluster']['python-version'] = '3.12.8'
-if platform?('amazon') && node['platform_version'] == "2"
-  default['cluster']['python-version'] = '3.9.20'
-end
 default['cluster']['python-major-minor-version'] = '3.12'
 if platform?('amazon') && node['platform_version'] == "2"
+  default['cluster']['python-version'] = '3.9.20'
   default['cluster']['python-major-minor-version'] = '3.9'
 end