Set minimum supported version to Kubernetes 1.24.0

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

CONTRIBUTING.md

@@ -68,8 +68,8 @@ for source changes.
 Prerequisites:
 
 * go >= 1.20
-* kubectl >= 1.20
-* kustomize >= 4.4
+* kubectl >= 1.24
+* kustomize >= 5.0
 * coreutils (on Mac OS)
 
 Install the [controller-runtime/envtest](https://github.com/kubernetes-sigs/controller-runtime/tree/master/tools/setup-envtest) binaries with:

cmd/flux/check.go

@@ -57,7 +57,7 @@ type checkFlags struct {
 }
 
 var kubernetesConstraints = []string{
-	">=1.20.6-0",
+	">=1.24.0-0",
 }
 
 var checkArgs checkFlags

cmd/flux/testdata/check/check_pre.golden

 ► checking prerequisites
-✔ Kubernetes {{ .serverVersion }} >=1.20.6-0
+✔ Kubernetes {{ .serverVersion }} >=1.24.0-0
 ✔ prerequisites checks passed