Variable defined in a subprocess' child is suggested in its input

[barmac]

Describe the bug

Any variables defined in the children of a subprocess appear in the code suggestions for that subprocess. However, these variables are not part of the subprocess scope.

Screen.Recording.2024-07-05.at.13.15.22.mov

Steps to reproduce

1. Create a subprocess
2. Add an element with output variable as a subprocess' child
3. Notice that the variable appears in the input suggestions

Expected behavior

In the input, I want to see only variables which can at least potentially be present. I don't want to see variables which can never be available in the element.

Environment

• OS: [e.g. MacOS 10.2, Windows 10]
• Camunda Modeler Version: [e.g. 2.0.0]
• Execution Platform: [e.g. Camunda 7, Camunda 8]
• Installed plug-ins: [...]

Additional context

No response

[barmac]

This came up at the implementation of #3951 where the variables available for start or end execution listener of a process are expected to be vastly different.