Create combined markdown report in weekly CI

[bernt-matthias]

I guess writing it to GITHUB_STEP_SUMMARY will still not work (because it's to large). But there is only one way to find out.

FOR CONTRIBUTOR:

• I have read the CONTRIBUTING.md document and this tool is appropriate for the tools-iuc repo.
• License permits unrestricted use (educational + commercial)
• This PR adds a new tool or tool collection
• This PR updates an existing tool or tool collection
• This PR does something else (explain below)

[mvdbeek]

It will definitely not work :).
In the CI action we could have another option to just post the summary, without details, and/or an option to just report the failing tool ids.

[bernt-matthias]

just post the summary

would it be an option to remove all the detailed infos of the successful tests?