chore(vdev): clean up clippy some allow statements

[divoxx]

Summary

First PR tackling the investigation and clean up of clippy allows in the repository.

As a first pass, this removes the allows that are possible to remove and narrows the scopes of the ones which are currently required.

Vector configuration

How did you test this PR?

cargo clippy and cargo test, and the suggested pre-push hook

Change Type

• [ ] Bug fix
• [ ] New feature
• [x] Non-functional (chore, refactoring, docs)
• [ ] Performance

Is this a breaking change?

• [ ] Yes
• [x] No

Does this PR include user facing changes?

• [ ] Yes. Please add a changelog fragment based on our guidelines.
• [x] No. A maintainer will apply the no-changelog label to this PR.

References

Related: https://github.com/vectordotdev/vector/issues/23659

Notes

• Please read our Vector contributor resources.
• Do not hesitate to use @vectordotdev/vector to reach out to us regarding this PR.
• Some CI checks run only after we manually approve them.
  • We recommend adding a pre-push hook, please see this template.
  • Alternatively, we recommend running the following locally before pushing to the remote branch:
    • make fmt
    • make check-clippy (if there are failures it's possible some of them can be fixed with make clippy-fix)
    • make test
• After a review is requested, please avoid force pushes to help us review incrementally.
  • Feel free to push as many commits as you want. They will be squashed into one before merging.
  • For example, you can run git merge origin master and git push.
• If this PR introduces changes Vector dependencies (modifies Cargo.lock), please run make build-licenses to regenerate the license inventory and commit the changes (if any). More details here.

[thomasqueirozb]

Hi @divoxx, can you sign the CLA? Thanks!

[thomasqueirozb]

Ping @divoxx

[github-actions[bot]]

Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

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I have read the CLA Document and I hereby sign the CLA

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2 out of 3 committers have signed the CLA.
:white_check_mark: (pront)[https://github.com/pront]
:white_check_mark: (thomasqueirozb)[https://github.com/thomasqueirozb]
:x: @divoxx
_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}