feat(ai): caching use deep copy for request table

[AntoineJac]

Summary

Same fix than:
https://github.com/Kong/kong-ee/pull/10059/files
Bug fix as request_table could be modified:
https://konghq.atlassian.net/browse/AG-111

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

Issue reference

Fix #[issue number]

[flrgh]

@AntoineJac

Please make the appropriate changes to get this PR in shape for merge:

• add changelog entry (it's fine to update an existing unreleased changelog entry or omit one if this is a fix for a not-yet-released feature)
• update the PR title and commit message
• add a reference to the the jira ticket in the PR description for tracking

[team-gateway-bot]

Git push to origin failed for release/3.8.x with exitcode 1

[team-gateway-bot]

Cherry-pick failed for master, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git remote add upstream https://github.com/kong/kong-ee
git fetch upstream master
git worktree add -d .worktree/cherry-pick-13566-to-master-to-upstream upstream/master
cd .worktree/cherry-pick-13566-to-master-to-upstream
git checkout -b cherry-pick-13566-to-master-to-upstream
ancref=$(git merge-base 168fbc0c97f521e9dcaebd1733fa60e9a7a062de e43812f6d989d9d728853bf0088bb29e1ef8cc63)
git cherry-pick -x $ancref..e43812f6d989d9d728853bf0088bb29e1ef8cc63

[kikito]

Notice this is missing the backport and cherrypicks, @AntoineJac