[24.1] Tighten axt sniffer

[martenson]

e.g. it would incorrectly sniff chain as axt since the comment line starts with "##matrix=axtChain"

How to test the changes?

(Select all options that apply)

• [ ] I've included appropriate automated tests.
• [x] This is a refactoring of components with existing test coverage.
• [ ] Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• [x] I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[martenson]

@bernt-matthias thanks for the suggestion! I added the test in https://github.com/galaxyproject/galaxy/pull/18204/commits/9ed4eda4b09a8f9fc626bb1ddcaa41ebf3885beb

[nsoranzo]

The failed integration test is relevant.