Adapt `run_spine.sh` to Handle a "Top Level" `yaml` with `include`s

[alexbooth92]

The yamls that are passed to the --config argument when running SPINE inference look like this:

# ND-LAr full chain configuration
# Revision date: March 10, 2026

include:
  - base/base_240819.yaml
  - io/io_240819.yaml
  - model/model_260310.yaml
  - post/post_240819.yaml

Our current run_spine.sh script assumes no includes (does a copy of the top level yaml to a tmp directory).

For a quick fix to be able to run a production step immediately, I just added a manual export of SPINE_CONFIG_PATH to, for example,

/pscratch/sd/d/dunepro/esabater/install/ND_Production/run-mlreco/install/spine_prod/config/infer/nd-lar

Long term, we could add a production environment var to look like this. I guess the tmp directory thing was first introduced to not have one file be hammered by lots of jobs at once? If so we should extend the tmp logic.