Update dependency dpctl to v0.21.0 (#2753)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.ci/pipeline/build-and-test-lnx.yml

@@ -65,7 +65,7 @@ steps:
       pip list
     env:
       NO_DPC: ${{ variables.NO_DPC }}
-      DPCTL_VERSION: 0.20.2
+      DPCTL_VERSION: 0.21.0
       DPNP_VERSION: 0.18.1
       DPCPP_RT_VERSION: 2025.3.0
     displayName: "Install testing requirements"

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  DPCTL_VERSION: 0.20.2
+  DPCTL_VERSION: 0.21.0
   DPNP_VERSION: 0.18.1
   DPCTL_PY_VERSIONS: '3.9\|3.11'
   UXL_PYTHONVERSION: "3.12"