[API Nodes]: auto-discover all nodes_*.py files

[bigcat88]

To avoid merge conflicts when adding new API nodes.

• Replaces hardcoded list of API node files with automatic discovery using glob
• New API nodes just need to follow the existing nodes_*.py naming convention

As a result:

• PRs adding new API nodes no longer conflict with each other
• No need to modify nodes.py when adding new API node files

[Kosinkadink]

Tested on my machine, seems to pick all partner node files, merging.