ext/standard: Removes ZPP style tests

[NickSdot]

ref: #23136 (review)

Commits:

1. removes the mentioned tests
2. removes additional candidates
3. restores lost coverage lines/branches

Coverage: ext/standard

Base: 16b3863d7ddd00872dcf6f2bbf5bb476174d0de2 upstream/master
Tree: a56499295f80b1c78d90865304a0cd73130fc1a6 working tree

+--------+-----------+---------+----------------------+----------------------+---------+----------+
|        |     Tests | Sources |                Lines |             Branches |    Time |   Memory |
+--------+-----------+---------+----------------------+----------------------+---------+----------+
| Base   |      3987 |      76 | 24829/30392 (81.70%) | 15737/24736 (63.62%) |  76.61s | 154.1 MB |
| Tree   |      3947 |      76 | 24829/30392 (81.70%) | 15737/24736 (63.62%) |  86.75s | 154.1 MB |
| Change | +17 / -57 |       0 |     +0 / -0 (+0.00%) |     +0 / -0 (+0.00%) | +10.14s |  +0.1 MB |
+--------+-----------+---------+----------------------+----------------------+---------+----------+

Edit: failure unrelated, rebase would probably fix but since everything else passes I will not tigger CI for that.