Thanks again.
I tried again and set:
export LD_LIBRARY_PATH=/usr/lib/cuda/lib64
and now see:
$ python -c "import tensorflow as tf;print(tf.reduce_sum(tf.random.normal([1000, 1000])))"
2021-11-17 18:25:24.770863: I tensorflow/core/platform/cpu_feature_guard.cc:151] This TensorFlow binary is optimized with oneAPI Deep Neural Network Library (oneDNN) to use the following CPU instructions in performance-critical operations:  AVX2 AVX512F FMA
To enable them in other operations, rebuild TensorFlow with the appropriate compiler flags.
2021-11-17 18:25:25.271273: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1525] Created device /job:localhost/replica:0/task:0/device:GPU:0 with 30985 MB memory:  -> device: 0, name: Tesla V100S-PCIE-32GB, pci bus id: 0000:d8:00.0, compute capability: 7.0
tf.Tensor(1303.674, shape=(), dtype=float32)

$ python3 -c 'import tensorflow as tf; print(tf.__version__)'
2.7.0

So I think that is successful?