e2e: bump main clusterctl upgrade test to 1.33

Signed-off-by: cprivitere <[email protected]>

Author: cprivitere

test/e2e/clusterctl_upgrade_test.go

@@ -339,7 +339,7 @@ var _ = Describe("When testing clusterctl upgrades using ClusterClass (v1.10=>cu
 			// Note: WorkloadKubernetesVersion should be the highest mgmt cluster version supported by the source Cluster API version.
 			// When picking this version, please check also the list of versions known by the source Cluster API version (rif. test/infrastructure/kind/mapper.go).
 			InitWithKubernetesVersion:   initKubernetesVersion,
-			WorkloadKubernetesVersion:   "v1.32.2", // NOTE: use v1.33 as soon as it is GA
+			WorkloadKubernetesVersion:   "v1.33.0",
 			MgmtFlavor:                  "topology",
 			WorkloadFlavor:              "topology",
 			UseKindForManagementCluster: true,