fix: re-add step dependencies, fix single step renders, and limit input nodes

[epmog]

What was the problem/requirement? (What/Why)

Three separate issues were identified:

1. Dependencies between steps were missing from generated job templates
2. Turning off "Submit Dependencies as Separate Steps" would submit the furthest node from deadline-cloud (and had ignore inputs in run data). So it would only ever render 1 node parametrized on frames
3. The deadline cloud node could have up to 1000 inputs. I don't believe this is necessarily a problem (though introduces more edge-cases) but for now could lead to confusion if you connect a deadline node multiple times in a single graph as compared to a more "legitimate" use-case of connecting to multiple separate graphs

What was the solution? (How)

1. A variable rename caused part of the step to overwrite itself thus losing the dependency_names info from the node, thus there were never any dependencies reported. Switching to a new, more useful variable name resolved the issue.
2. The intent with that mode is to submit the whole graph as a step, parameterized on frames. This was a quick fix of choosing the last node in the step nodes, since that'll be the one connected to the deadline-cloud node. It might still be wrong as I haven't exercised all cases, but it's more correct. Also removed any step deps generation
3. Limited the node to 1 input, users can always create more nodes wherever they would have used this information.

What is the impact of this change?

Criticial features (dependencies/no-dependencies) are working again!

How was this change tested?

hatch run fmt
hatch build
hatch run lint
hatch run test
hatch shell
rm -rf ./plugin_env
hatch run install

launched houdini

submitted some jobs with dependencies to the service

verified that when submitting without deps, that the node closest to deadline-cloud is submitted with ignore_inputs set to false so it renders the whole graph

Was this change documented?

n/a

Is this a breaking change?

Fixing!