[9.1](backport #45159) chore: bump github.com/prometheus/prometheus to v0.304.1

[mergify]

Proposed commit message

Update github.com/prometheus/prometheus to v0.304.1.

This is needed to update OTel Collector components to v0.129.0 in Elastic Agent repository, as the Prometheus receiver depends on github.com/prometheus/prometheus v0.304.1.

The one code change is a result of a breaking change introduced in prometheus/prometheus#16012.

Checklist

• My code follows the style guidelines of this project
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have made corresponding change to the default configuration files
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

How to test this PR locally

(cd metricbeat && mage build)
```<hr>This is an automatic backport of pull request #45159 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 621c6c3 has failed:

On branch mergify/bp/9.1/pr-45159
Your branch is up to date with 'origin/9.1'.

You are currently cherry-picking commit 621c6c3ea.
  (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:   NOTICE.txt
	modified:   metricbeat/helper/prometheus/textparse.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod
	both modified:   go.sum

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

[github-actions]

🤖 GitHub comments

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Just comment with:

• run docs-build : Re-trigger the docs validation. (use unformatted text in the comment!)

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b mergify/bp/9.1/pr-45159 upstream/mergify/bp/9.1/pr-45159
git merge upstream/9.1
git push upstream mergify/bp/9.1/pr-45159

[mergify]

This pull request has not been merged yet. Could you please review and merge it @andrzej-stencel? 🙏