Fix querier panics

[joe-elliott]

What this PR does:
A panic was introduced here by abusing the ring forEach function to collect results. replicationSet.Do can return before all reads are complete if quorum is reached. Under certain, rare circumstances this caused the forEach function to modify a result here after it has already been returned and was being marshalled by the gRPC stack into proto.

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[github-actions]

The backport to release-v2.7 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new branch
git switch --create backport-4790-to-release-v2.7 origin/release-v2.7
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 6d707056521ce46c79179fc16fc12126579f66a0

When the conflicts are resolved, stage and commit the changes:

git add . && git cherry-pick --continue

If you have the GitHub CLI installed:

# Push the branch to GitHub:
git push --set-upstream origin backport-4790-to-release-v2.7
# Create the PR body template
PR_BODY=$(gh pr view 4790 --json body --template 'Backport 6d707056521ce46c79179fc16fc12126579f66a0 from #4790{{ "\n\n---\n\n" }}{{ index . "body" }}')
# Create the PR on GitHub
echo "${PR_BODY}" | gh pr create --title '[release-v2.7] Fix querier panics' --body-file - --label 'type/bug' --label 'backport' --base release-v2.7 --milestone release-v2.7 --web

Or, if you don't have the GitHub CLI installed (we recommend you install it!):

# Push the branch to GitHub:
git push --set-upstream origin backport-4790-to-release-v2.7

# Create a pull request where the `base` branch is `release-v2.7` and the `compare`/`head` branch is `backport-4790-to-release-v2.7`.

# Remove the local backport branch
git switch main
git branch -D backport-4790-to-release-v2.7