Renamed infra/image/inventory to build-inventory, dropped interpreter

This change also removed ansible_python_interpreter setting in the
inventory as the interpreter should be discovered by ansible for the
distributions.

The dockerfiles have been adapted to not force the installation of
python3 for CentOS-Stream 8, 9 and 10.

infra/image/build-inventory

@@ -0,0 +1,15 @@
+[ipaserver]
+ansible-freeipa-image-builder ansible_connection=podman
+
+[ipaserver:vars]
+ipaadmin_password=SomeADMINpassword
+ipadm_password=SomeDMpassword
+ipaserver_domain=test.local
+ipaserver_realm=TEST.LOCAL
+ipaserver_setup_dns=true
+ipaserver_auto_forwarders=true
+ipaserver_no_dnssec_validation=true
+ipaserver_auto_reverse=true
+ipaserver_setup_kra=true
+ipaserver_setup_firewalld=false
+ipaclient_no_ntp=true