core: SignAnchorspend requires approval in ENFORCING mode

Summary

All details described in #488

Since #488 has an stm32-specific issue (needs approver GUI for onchain) this tracks the core issue that SignAnchorspend shouldn't require additional approval.

I believe the same issue exists in VLS_MODE=cln:socket but have not verified. It may be that our export VLS_AUTOAPPROVE=1 in testing is covering this up?

If transactions are returning funds to the wallet they shouldn't require additional approval.

If the test is doing something weird like closing to a non-wallet address than this should be added to the testing allowlist.