refactor ibc ante_test

[colin-axner]

Description

ref: #5558

blocked on: #6611

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #6610 into master will increase coverage by 7.37%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6610      +/-   ##
==========================================
+ Coverage   50.36%   57.74%   +7.37%     
==========================================
  Files         243      495     +252     
  Lines       13137    29664   +16527     
==========================================
+ Hits         6617    17130   +10513     
- Misses       6010    11301    +5291     
- Partials      510     1233     +723     

[colin-axner]

this is r4r, one test just fails on the issue this is blocked on. Pending that change it should be good to go

[fedekunze]

ACK pending test fix

[AdityaSripal]

approved, pending unblocking issue