Fix: add missing uv.source for simple_calculator_hitl

[willkill07]

Description

When installing the example in a standalone manner, we get an error:

warning: Missing version constraint (e.g., a lower bound) for `nat-por-to-jiratickets`
warning: Missing version constraint (e.g., a lower bound) for `sphinx-mermaid`
  × No solution found when resolving dependencies:
  ╰─▶ Because only the following versions of nvidia-nat[langchain] are available:
          nvidia-nat[langchain]<1.2
          nvidia-nat[langchain]>=2.dev0
      and nat-por-to-jiratickets==1.2.0rc6.dev9+gc0055ac2.d20250812 depends on nvidia-nat[langchain]>=1.2,<2.dev0, we can conclude that
      nat-por-to-jiratickets==1.2.0rc6.dev9+gc0055ac2.d20250812 cannot be used.
      And because nat-por-to-jiratickets was not found in the package registry and nat-simple-calculator-hitl==1.2.0rc6.dev20+gd94ec677.d20250813 depends
      on nat-por-to-jiratickets, we can conclude that nat-simple-calculator-hitl==1.2.0rc6.dev20+gd94ec677.d20250813 cannot be used.
      And because only nat-simple-calculator-hitl==1.2.0rc6.dev20+gd94ec677.d20250813 is available and you require nat-simple-calculator-hitl, we can
      conclude that your requirements are unsatisfiable.

This PR adds the missing source dependency for nat_por_to_jiratickets

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• When the PR is ready for review, new or existing tests cover these changes.
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[willkill07]

/merge