fix: Soft-replacement of `resolve_conflicts` arg in aws_eks_addon

[LeoSpyke]

Description

Replaces the resolve_conflicts argument of aws_eks_addon resource with the new resolve_conflicts_on_create and resolve_conflicts_on_update. By doing so, the warning is removed.

Motivation and Context

The resolve_conflicts argument is actually deprecated.

Breaking Changes

No breaking changes introduced with this PR as old configurations (since hashicorp/aws>=4.47 as specified in versions.tf) are still compatible as resolve_conflicts it still used in a first attempt. This could be considered as a first step that removes the warning and, in a future fix, will eventually remove the compatibility with the old parameter. With this change in place, a subsequent plan after the modules upgrade, will only trigger an "update in-place", nothing else is required and no resource replacement is needed.

How Has This Been Tested?

• [x] ~~I have updated at least one of the examples/* to demonstrate and validate my change(s)~~ (none of the examples provided is actually using such parameter, anyway the change is transparent)
• [x] ~~I have tested and validated these changes using one or more of the provided examples/* projects~~ (same as above)
• [x] I have executed pre-commit run -a on my pull request