fix(gha): use regctl for (multiarch) image copy

[curiositycasualty]

Summary

This PR pivots the docker hub re-tagging portions of the release github action to utilize regctl image copy instead of plain ole' docker pull.
The docker pull approach lacked support for multi-architecture builds, result in only amd64 image tags being added to unofficial/official repos.

Sister PR to: https://github.com/Kong/kong-ee/pull/4624

Checklist

• The Pull Request has tests
• There's an entry in the CHANGELOG
• There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE

Full changelog

Issue reference

Fix #[issue number]

[mashapedeployment]

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-10335-to-release/3.2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 b5d01ecbcfe6c990f49cee4d8279b4b4267c0373
# Push it to GitHub
git push --set-upstream origin backport-10335-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-10335-to-release/3.2.x.