[Bug]: Scheduled CI job requirements delay completion

[BradyPlanden]

Python Version

N/A

Describe the bug

With the recent changes to the scheduled workflow in #308, the build job had filter_pybamm_matrix removed as a requirement. This was in place to avoid the github runners being tied up with running the tests before the matrix was built so that the self-host runner could start.

Steps to reproduce the behaviour

Under certain conditions, the scheduled tests will be delayed as the self-hosted runner will be delayed in starting.

Relevant log output

No response