Add semantic YAML diff PR comments via shared workflow

.github/workflows/validate.yaml

@@ -7,7 +7,7 @@ on:
 
 env:
   kubeconform_ver: "0.4.13"
-  dyff_ver: "1.5.4"
+  dyff_ver: "1.7.1"
   clusterctl_ver: "1.2.0"
   apptestctl_ver: "0.18.0"
   kind_ver: "0.12.0"

.github/workflows/yaml-diff.yaml

@@ -0,0 +1,12 @@
+name: yaml-diff
+
+on:
+  pull_request:
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  yaml-diff:
+    uses: giantswarm/github-workflows/.github/workflows/yaml-diff.yaml@main

CHANGELOG.md

@@ -5,8 +5,21 @@ following [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
 
+### Added
+
+- Semantic YAML diff PR comments via the new `yaml-diff` workflow
+  (calls `giantswarm/github-workflows/.github/workflows/yaml-diff.yaml`).
+  Key reordering without value changes no longer shows up as noise in PR
+  reviews. Alphabetical key-ordering enforcement in `.yamllint` is
+  unchanged in this release; it will be dropped in a follow-up once the
+  bot has run on real PRs.
+  See [giantswarm/roadmap#4121](https://github.com/giantswarm/roadmap/issues/4121).
+
 ### Changed
 
+- Bump `dyff_ver` from `1.5.4` to `1.7.1` in the existing rendered-manifest
+  diff job (`validate.yaml`), to standardize on the version used by the new
+  `yaml-diff` workflow.
 - migrated `.spec.config` to `.spec.extraConfigs`
 - Templates: Rename `nginx-ingress-controller` to `ingress-nginx`. ([#85](https://github.com/giantswarm/gitops-template/pull/85))