fix(meshfaultinjection): deprecate spec.from field

[Automaat]

Motivation

spec.from in MeshFaultInjection is superseded by spec.rules which provides equivalent functionality. Deprecating spec.from steers users toward the preferred API.

Implementation information

Added 'from' field is deprecated, use 'rules' instead deprecation warning when spec.from is non-empty, consistent with the pattern used in MeshTimeout, MeshRateLimit, and other policies. Existing MeshService-kind deprecation warning is preserved and nested inside the from check.

Supporting documentation

Fix #12380

Changelog: fix(meshfaultinjection): deprecate spec.from field

[Copilot]

Pull request overview

Deprecates the spec.from field in the MeshFaultInjection policy API by emitting a deprecation warning when the field is used, steering users toward the newer spec.rules API (per issue #12380).

Changes:

• Add a deprecation warning when spec.from is non-empty: "'from' field is deprecated, use 'rules' instead".
• Preserve the existing deprecation warning for MeshService in from[].targetRef.kind, now emitted only when spec.from is present.
• Keep TopLevelTargetRefDeprecations(spec.targetRef) included in the returned warnings.

[github-actions]

Reviewer Checklist

🔍 Each of these sections need to be checked by the reviewer of the PR 🔍:
If something doesn't apply please check the box and add a justification if the reason is non obvious.

• Is the PR title satisfactory? Is this part of a larger feature and should be grouped using > Changelog?
• PR description is clear and complete. It Links to relevant issue as well as docs and UI issues
• This will not break child repos: it doesn't hardcode values (.e.g "kumahq" as an image registry)
• IPv6 is taken into account (.e.g: no string concatenation of host port)
• Tests (Unit test, E2E tests, manual test on universal and k8s)
  • Don't forget ci/ labels to run additional/fewer tests
• Does this contain a change that needs to be notified to users? In this case, UPGRADE.md should be updated.
• Does it need to be backported according to the backporting policy? (this GH action will add "backport" label based on these file globs, if you want to prevent it from adding the "backport" label use no-backport-autolabel label)