tests/sanity/ignore-2.12.txt: Remove unnecessary entries

ERROR: Found 2 pylint issue(s) which need to be resolved:

ERROR: tests/sanity/ignore-2.12.txt:3:1: ansible-test: Ignoring
'ansible-bad-import-from' on
'plugins/module_utils/ansible_freeipa_module.py' is unnecessary

ERROR: tests/sanity/ignore-2.12.txt:5:1: ansible-test: Ignoring
'ansible-format-automatic-specification' on
'plugins/module_utils/ansible_freeipa_module.py' is unnecessary