[7.17](backport #4475) Remove Team:Fleet from dependabot.yml

[mergify]

What is the problem this PR solves?

Dependabot PR's ping Team:Fleet unnecessarily.

How does this PR solve the problem?

Removes the Team:Fleet label from dependabot config.

How to test this PR locally

N/A

---

This is an automatic backport of pull request #4475 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of b2de632 has failed:

On branch mergify/bp/7.17/pr-4475
Your branch is up to date with 'origin/7.17'.

You are currently cherry-picking commit b2de632.
  (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)

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	deleted by us:   .github/dependabot.yml

no changes added to commit (use "git add" and/or "git commit -a")

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

[mergify]

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

[mergify]

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

[v1v]

dependabot is not needed in branches but in the default branch