fix(dns): Eliminate asynchronous timer in syncQuery() to prevent hang risk

[chobits]

Summary

Originally the first request to syncQuery() will trigger an asynchronous timer event, which added the risk of the thread pool hanging in the timerng library. With this patch, it will perform a synchronously DNS query for the first time if current phase is yieldable.

Checklist

• The Pull Request has tests
• A changelog file has been created under changelog/unreleased/kong or skip-changelog label added on PR if changelog is unnecessary. README.md
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Full changelog

• syncQuery() will perform a synchronously DNS query for the first time if current phase is yieldable.
  • Keep the original async query using event timer for some unyieldable phase like init_worker_by_lua.
• simplify the logic of yieldable checking by using kong.tools.yield.in_yieldable_phase()
• simplify executeQuery() by using individualQuery()
• revert fix(dns): set default dns_no_sync to on #11869

Issue reference

Fix KAG-2913 FTI-5348

[team-gateway-bot]

The backport to release/3.2.x 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 working tree
git worktree add .worktrees/backport-release/3.2.x release/3.2.x
# Navigate to the new working tree
cd .worktrees/backport-release/3.2.x
# Create a new branch
git switch --create backport-11900-to-release/3.2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 a6d647566991e339ea5126113df4bef21fe0115d
# Push it to GitHub
git push --set-upstream origin backport-11900-to-release/3.2.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release/3.2.x

Then, create a pull request where the base branch is release/3.2.x and the compare/head branch is backport-11900-to-release/3.2.x.

[team-gateway-bot]

The backport to release/3.3.x 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 working tree
git worktree add .worktrees/backport-release/3.3.x release/3.3.x
# Navigate to the new working tree
cd .worktrees/backport-release/3.3.x
# Create a new branch
git switch --create backport-11900-to-release/3.3.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 a6d647566991e339ea5126113df4bef21fe0115d
# Push it to GitHub
git push --set-upstream origin backport-11900-to-release/3.3.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release/3.3.x

Then, create a pull request where the base branch is release/3.3.x and the compare/head branch is backport-11900-to-release/3.3.x.