[Directories] Set /etc permissions to 0755.

This is the default permission in Linux, but it was unintentionally changed in Rocky9.4 (https://forums.rockylinux.org/t/changed-permissions-on-etc-in-rl9-4-genericcloud-image/14449) breaking Munge, which requires the folder to be 0755.

Signed-off-by: Giacomo Marciani <mgiacomo@amazon.com>

cookbooks/aws-parallelcluster-platform/recipes/install/directories.rb

@@ -29,3 +29,13 @@
   mode '1777'
   recursive true
 end
+
+# The default permission for directory /etc is 0755.
+# However, in Rocky9.4 it was unintentionally changed to 0777,
+# causing issues with Munge, that fails to start if /etc has group-writable permission without sticky bit.
+# See https://forums.rockylinux.org/t/changed-permissions-on-etc-in-rl9-4-genericcloud-image/14449
+directory '/etc' do
+  owner 'root'
+  mode '0755'
+  recursive false
+end