CI fails to build necessary ports when changing specific supervisor file

[jepler]

CircuitPython version

origin/main

Code/REPL

$ python3 tools/ci_set_matrix.py supervisor/shared/web_workflow/web_workflow.c supervisor/shared/web_workflow/web_workflow.c
Using files list on commandline
Using jobs list in LAST_FAILED_JOBS
::group::Log: changed_files
{'supervisor/shared/web_workflow/web_workflow.c'}
::endgroup::
::group::Log: last_failed_jobs
{}
::endgroup::
Running: conditionally
Building docs: False
Would set GitHub actions output docs to 'False'
Building windows: False
Would set GitHub actions output windows to 'False'
Building boards: False
Would set GitHub actions output ports to '{}'

Behavior

No boards are built. Instead, any board that uses web workflow should be built.

Description

No response

Additional information

No response

[jepler]

This problem was encountered "in the wild" in #8371.

[jepler]

it looks like I introduced it. PR forthcoming after S&T