bug: our CI has no report for changes to workflow definition

[philclifford]

The Mandatory CI testing blocks waiting for return for some changes such as updates to workflows (e.g. #1286 ) and prevents merging.

We need to handle untested changes or develop tests.

[philclifford]

The main problem seems to be that we are filtering out changes to markdown and other text files (including workflow defs) from testing so if that's all that is changed CI waits for ever.

We probably need to

• add markdown lint (passing but warning, with an appropriate config)
• add a catch-all no-code-affected report matching the required flow name(s) so the nothing failed state always returns something