docs: note kustomize-set-image tag/digest requirement (#3581)

Signed-off-by: Jesse Suen <[email protected]>
(cherry picked from commit 29e6fb8)

Author: jessesuen

docs/docs/80-release-notes/96-v1.3.0.md

@@ -3,6 +3,7 @@
 As announced in our [`v1.1.0` release notes](https://github.com/akuity/kargo/releases/tag/v1.1.0), several deprecated features from _before_ we introduced support for Expression Language have been removed in this release.
 
 - The `fromOrigin` and `fromFreight` fields in the [`argocd-update`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/argocd-update), [`git-clone`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/git-clone/), [`helm-update-chart`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/helm-update-chart/), and [`kustomize-set-image`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/kustomize-set-image/) steps have been removed in favor of the [expression functions](https://docs.kargo.io/user-guide/reference-docs/expressions#functions).
+- The [`kustomize-set-image`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/kustomize-set-image/) step no longer implicitly sets the tag from the Freight image and users must specify either the `tag` or `digest` they wish to set (e.g. using `imageFrom` function).
 - The `<thing>FromStep` fields in the [`argocd-update`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/argocd-update), [`git-open-pr`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/git-open-pr/), and [`git-wait-for-pr`](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/git-wait-for-pr/) steps have been removed in favor of using [step outputs](https://docs.kargo.io/user-guide/reference-docs/expressions#pre-defined-variables).
 - The `helm-update-image` step has been removed in favor of the more generic [`yaml-update` step](https://docs.kargo.io/user-guide/reference-docs/promotion-steps/yaml-update) which supports the same functionalities.