Add comment explaining the purpose of the filtering job

[backmari]

Description

This PR tests the CI jobs triggered on a PR from a fork. Note that this is a PR into the feature branch #3866.

Fixes # (issue/issues)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce.

Review Checklist:

[if using the editor, use [x] in place of [ ] to check a box]

Documentation (check at least one)

• There is nothing that needs documenting
• Documentation changes are in this PR
• There is an issue open for the documentation (link?)

Installers

• There is a chance this will affect the installers, if so
  • Windows installer (GH artifact) has been tested (installed and worked)
  • MacOSX installer (GH artifact) has been tested (installed and worked)
  • Wheels installer (GH artifact) has been tested (installed and worked)

Licensing (untick if necessary)

• The introduced changes comply with SasView license (BSD 3-Clause)

[krzywon]

@backmari - This seems like a small change. Was this meant as a test to see if the CI would trigger from forks, or do you want this merged? If the latter, I will approve and merge.

[backmari]

@krzywon Yes to both 🙂 It was mostly to test triggering the CI from a fork, but I would also like to add this comment to the other branch so if you would approve and merge, that would be great!