re-allow using RelatedNode as input to cardinality=one rel

[ajtmccarty]

fixes #452

we accidentally included a breaking change in version 1.13.1. we stopped allowing passing a RelatedNode as an input when creating a new InfrahubNode. This PR makes that possible again

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[codecov]

Codecov Report

Attention: Patch coverage is 78.94737% with 4 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
infrahub_sdk/node/node.py	78.94%	2 Missing and 2 partials ⚠️

@@           Coverage Diff           @@
##           stable     #453   +/-   ##
=======================================
  Coverage   75.57%   75.58%           
=======================================
  Files         100      100           
  Lines        8751     8769   +18     
  Branches     1704     1712    +8     
=======================================
+ Hits         6614     6628   +14     
- Misses       1661     1665    +4     
  Partials      476      476           

Flag	Coverage Δ
integration-tests	34.62% <26.31%> (-0.02%)	⬇️
python-3.10	47.90% <73.68%> (+0.03%)	⬆️
python-3.11	47.90% <73.68%> (+0.03%)	⬆️
python-3.12	47.90% <73.68%> (+0.06%)	⬆️
python-3.13	47.90% <73.68%> (+0.06%)	⬆️
python-3.9	46.57% <73.68%> (+0.06%)	⬆️
python-filler-3.12	25.23% <5.26%> (-0.06%)	⬇️

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Files with missing lines	Coverage Δ
infrahub_sdk/node/node.py	75.19% <78.94%> (+0.06%)	⬆️

... and 2 files with indirect coverage changes

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