Include `kontrol prove` command in the XML report

[palinatolmach]

As suggested by @lisandrasilva, we might want to include the kontrol prove command that generated this report into the XML report (so we can see what flags were used). And also, if the test-suite belongs to a GH repo, what is the commit-hash corresponding to the generated report.

For instance:

<testsuites tests="24" failures="2" errors="0" time="3227.6390516757965" timestamp="2024-09-25 14:55:28.227190" kontrol-cli-cmd= "kontrol prove --maintenance-rate 24 --xml-test-report" commit-hash="26677b899f162392c8f4a30ef4e8800f4a030613">