message: Update Dockerfile.tf-plugin by update cuda to 11.2.1, tf to 2.6
diff: # See the License for the specific language governing permissions and
  # limitations under the License.
  -ARG CUDA_VERSION=11.1.1
  +ARG CUDA_VERSION=11.2.1
  ARG CUDNN_VERSION=8
  ARG UBUNTU_VERSION=20.04
  FROM nvidia/cuda:${CUDA_VERSION}-cudnn${CUDNN_VERSION}-devel-ubuntu${UBUNTU_VERSION} AS devel
  @@ -20,7 +20,7 @@ FROM nvidia/cuda:${CUDA_VERSION}-cudnn${CUDNN_VERSION}-devel-ubuntu${UBUNTU_VERS
  ARG CMAKE_VERSION=3.19.6
  ARG PYTHON_VERSION=3.8
  ARG RAPIDS_VERSION=21.06
  -ARG TF_VERSION=2.4.0
  +ARG TF_VERSION=2.6.0
  ARG RELEASE=false
  ARG SM="70;75;80"
  