tests: Test Taproot PSBT signing with keys in other descriptor
tests: Test Taproot PSBT signing with keys in other descriptor

Test that the same keys included in other descriptors will still be able
to sign a PSBT that requires those keys.

Github-Pull: #26418
Rebased-From: 0de30ed509a9969cb254e00097671625c9e107d2

fujicoin/fujicoin,fujicoin/fujicoin,fujicoin/fujicoin,fujicoin/fujicoin,fujicoin/fujicoin,fujicoin/fujicoin