Bump azure/setup-kubectl from 3.2 to 4

Bumps [azure/setup-kubectl](https://github.com/azure/setup-kubectl) from 3.2 to 4.
- [Release notes](https://github.com/azure/setup-kubectl/releases)
- [Changelog](https://github.com/Azure/setup-kubectl/blob/main/CHANGELOG.md)
- [Commits](Azure/setup-kubectl@v3.2...v4)

---
updated-dependencies:
- dependency-name: azure/setup-kubectl
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/delius-core-cp-rds-data-refresh.yaml

@@ -58,7 +58,7 @@ jobs:
       - uses: actions/checkout@v4.1.1
 
       - name: Install kubectl
-        uses: azure/setup-kubectl@v3.2
+        uses: azure/setup-kubectl@v4
         with:
           version: 'v1.26.0' # default is latest stable
         id: kubectl_install