fix(buf): set correct prefix for api (backport #4198)

[mergify]

Closes: #4174

---

This is an automatic backport of pull request #4198 done by Mergify.

[mergify]

Cherry-pick of 1316d69 has failed:

On branch mergify/bp/release/v28.x.y/pr-4198
Your branch is up to date with 'origin/release/v28.x.y'.

You are currently cherry-picking commit 1316d694.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   changelog.md

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	added by us:     ignite/templates/app/files/proto/buf.gen.pulsar.yaml
	added by them:   ignite/templates/app/files/proto/buf.gen.pulsar.yaml.plush
	both deleted:    ignite/templates/app/files/{{protoDir}}/buf.gen.pulsar.yaml
	deleted by us:   ignite/templates/app/proto_test.go
	deleted by us:   integration/app/cmd_proto_path_test.go

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 25.98%. Comparing base (232b10d) to head (552767c).
Report is 26 commits behind head on release/v28.x.y.

Additional details and impacted files

@@                 Coverage Diff                 @@
##           release/v28.x.y    #4200      +/-   ##
===================================================
+ Coverage            24.74%   25.98%   +1.23%     
===================================================
  Files                  297      300       +3     
  Lines                24979    25535     +556     
===================================================
+ Hits                  6182     6635     +453     
- Misses               18230    18322      +92     
- Partials               567      578      +11     

see 2 files with indirect coverage changes