[Supplier] refactor: SupplierStakingFee var usage to param usage

[bryanchriswhite]

Summary

Replace usage of supplierkeeper.SupplierStakingFee with the new param and delete it.

Issue

• TODO_BETA

Type of change

Select one or more from the following:

• New feature, functionality or library
• Consensus breaking; add the consensus-breaking label if so. See [Infra] Automatically add the consensus-breaking label #791 for details
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Testing

• Documentation: make docusaurus_start; only needed if you make doc changes
• Unit Tests: make go_develop_and_test
• LocalNet E2E Tests: make test_e2e
• DevNet E2E Tests: Add the devnet-test-e2e label to the PR.

Sanity Checklist

• I have tested my changes using the available tooling
• I have commented my code
• I have performed a self-review of my own code; both comments & source code
• I create and reference any new tickets, if applicable
• I have left TODOs throughout the codebase, if applicable

[github-actions]

The CI will now also run the e2e tests on devnet, which increases the time it takes to complete all CI checks.

You may need to run make trigger_ci to submit an empty commit that'll trigger the tests.

GCP workloads (requires changing the namespace to 948)
Grafana network dashboard for devnet-issue-948