fix: replace deprecated codec.ProtoMarshaler interface with proto.Message

[MozirDmitriy]

Description

• In testing/utils.go, replaced the parameter type in the UnmarshalMsgResponses function from codec.ProtoMarshaler to proto.Message and added the necessary import
• In e2e/testsuite/codec.go, also replaced the parameter type in the identically named function

Replacing the deprecated interface helps avoid potential issues in the future when codec.ProtoMarshaler might be completely removed from the codebase. Using the recommended proto.Message interface aligns with SDK development best practices.
The interface replacement maintains the same functionality as the implementation of the functions doesn't use any specific methods of the codec.ProtoMarshaler interface that aren't available in proto.Message.

---

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 the 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 and Go style guide.
• Wrote unit and integration tests.
• Updated relevant documentation (docs/).
• Added relevant godoc comments.
• Provide a conventional commit message to follow the repository standards.
• Include a descriptive changelog entry when appropriate. This may be left to the discretion of the PR reviewers. (e.g. chores should be omitted from changelog)
• Re-reviewed Files changed in the GitHub PR explorer.
• Review SonarCloud Report in the comment section below once CI passes.

[gjermundgaraba]

Sorry for the long wait here! Could you please also add a changelog entry for this under ### Testing API in CHANGELOG.md?

Otherwise, I think this looks good and useful 🙏 Thank you!

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 61.62%. Comparing base (b509a83) to head (be9a1dd).

Files with missing lines	Patch %	Lines
e2e/testsuite/codec.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8366   +/-   ##
=======================================
  Coverage   61.62%   61.62%           
=======================================
  Files         299      299           
  Lines       21462    21462           
=======================================
  Hits        13227    13227           
  Misses       7643     7643           
  Partials      592      592           

Flag	Coverage Δ
08-wasm	66.28% <ø> (ø)
e2e	1.18% <0.00%> (ø)
ibc-go	67.71% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[MozirDmitriy]

Sorry for the long wait here! Could you please also add a changelog entry for this under ### Testing API in CHANGELOG.md?

Otherwise, I think this looks good and useful 🙏 Thank you!

Sorry for late answear, i've added changelog, thanks for review

[MozirDmitriy]

@DeshErBojhaa Yes, sorry