Migrate to new spoom srb coverage command

[JamieMagee]

What are you trying to accomplish?

Fix the spoom coverage report generation.

It hasn't been generating a new report since 24th April due to the command we were using being deprecated.

Related to #9876

Anything you want to highlight for special attention from reviewers?

How will you know you've accomplished your goal?

The deprecation warning is gone and the report is being generated again.

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.