Remove unused codecov for Orquesta integration tests

[arm4b]

A follow-up to #6046 and #6036

Per https://github.com/StackStorm/st2/actions/runs/6626784565/job/18001200008#step:17:124 there is no coverage generated for Orquesta integration tests:

info - 2023-10-24 12:58:34,396 -- Generating coverage.xml report in /home/runner/work/st2/st2
info - 2023-10-24 12:58:34,520 -- No data to report.
info - 2023-10-24 12:58:34,639 -- Found 0 coverage files to upload
Error: No coverage reports found. Please make sure you're generating reports successfully.
Error: Process completed with exit code 1.

and based on https://app.codecov.io/gh/StackStorm/st2/commits we never generated it before (coverage % is the same).

Remove the respective codecov step from the GH Workflows as it 🔴 the master builds.
Hope it's the last PR to fix the stackstorm/st2 build failure noise.