Merge #13138: [tests] Remove accounts from wallet_importprunedfunds.py

Summary:
38040c34e1 [tests] Remove accounts from wallet_importprunedfunds.py (John Newbery)

Pull request description:

This was split from #13075 to not block review/merge of that PR.

Tree-SHA512: 631d7139ed2bda5222ec395cc75720261e2e1f741dba04723d09fe04ef6cf92222a3679d886026ec33e2db2d1e2fa1a0f36c2451581d0f733a9939a98c7118ab

Backport of Core PR13138
https://github.com/bitcoin/bitcoin/pull/13138/

Depends on D4540

Test Plan:

test_runner.py wallet_importprunedfunds

Reviewers: deadalnix, Fabien, jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: Fabien, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D4541