op-acceptance-tests: run TestFollowL2_WithoutCLP2P against kona-node

## Summary

[`TestFollowL2_WithoutCLP2P`](https://github.com/ethereum-optimism/optimism/blob/develop/op-acceptance-tests/tests/sync/follow_l2/sync_test.go) is skipped when the acceptance suite runs against kona-node.

The single-chain test-sequencer/follow-source preset currently requires an op-node CL.

## Required work

Generalize the preset around backend-neutral follow-source capabilities, supply the Kona implementation, and remove the Kona skip.

## Acceptance criteria

- [ ] The root cause and resolution are documented.
- [ ] `TestFollowL2_WithoutCLP2P` no longer skips when `DEVSTACK_L2CL_KIND=kona-node`.
- [ ] Kona follows L2 correctly without CL P2P, and the scenario continues to pass with op-node.
- [ ] Existing op-node coverage continues to pass.

## Related

- https://github.com/ethereum-optimism/optimism/issues/18800
- https://github.com/ethereum-optimism/optimism/issues/18674
- https://github.com/ethereum-optimism/optimism/issues/18675
- https://github.com/ethereum-optimism/optimism/issues/20718
- Parent inventory: https://github.com/ethereum-optimism/protocol-team/issues/101