NameError: name 'filter_config' is not defined on main branch

[rsleedbx]

looks like this was introduced with #162 @azun @danielcoman

Expected Behaviour

CLI example works as advertised.

himl examples/complex/env=dev/region=us-east-1/cluster=cluster2

Actual Behaviour

running the examples results in NameError: name 'filter_config' is not defined

Traceback (most recent call last):
  File "/opt/homebrew/bin/himl", line 8, in <module>
    sys.exit(run())
             ^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/himl/main.py", line 84, in run
    ConfigRunner().run(args)
  File "/opt/homebrew/lib/python3.11/site-packages/himl/main.py", line 30, in run
    self.do_run(opts)
  File "/opt/homebrew/lib/python3.11/site-packages/himl/main.py", line 41, in do_run
    config_processor.process(cwd, opts.path, filters, filter_config, excluded_keys, opts.enclosing_key, opts.remove_enclosing_key,
                                                      ^^^^^^^^^^^^^
NameError: name 'filter_config' is not defined

Reproduce Scenario (including but not limited to)

README.md example should work

Steps to Reproduce

git clone https://github.com/adobe/himl.git
cd himl
himl examples/complex/env=dev/region=us-east-1/cluster=cluster2

Platform and Version

Sample Code that illustrates the problem

bash-5.2$ git clone https://github.com/adobe/himl.git
cd himl
himl examples/complex/env=dev/region=us-east-1/cluster=cluster2
Cloning into 'himl'...
remote: Enumerating objects: 1069, done.
remote: Counting objects: 100% (323/323), done.
remote: Compressing objects: 100% (42/42), done.
remote: Total 1069 (delta 302), reused 286 (delta 281), pack-reused 746
Receiving objects: 100% (1069/1069), 195.73 KiB | 2.08 MiB/s, done.
Resolving deltas: 100% (638/638), done.
Traceback (most recent call last):
  File "/opt/homebrew/bin/himl", line 8, in <module>
    sys.exit(run())
             ^^^^^
  File "/opt/homebrew/lib/python3.11/site-packages/himl/main.py", line 84, in run
    ConfigRunner().run(args)
  File "/opt/homebrew/lib/python3.11/site-packages/himl/main.py", line 30, in run
    self.do_run(opts)
  File "/opt/homebrew/lib/python3.11/site-packages/himl/main.py", line 41, in do_run
    config_processor.process(cwd, opts.path, filters, filter_config, excluded_keys, opts.enclosing_key, opts.remove_enclosing_key,
                                                      ^^^^^^^^^^^^^
NameError: name 'filter_config' is not defined

Logs taken while reproducing problem

see above