Add yaml as a Webdataset test dependency, adjust to new WDS API

- the latest webdataset python package caries silent yaml
  dependency what break DALI test. This PR adds a missing package
  to the installation process.
- removes a usage of the `shardshuffle` parameters in webdataset
  example as it is no longer available in webdataset API

Signed-off-by: Janusz Lisiecki <jlisiecki@nvidia.com>

docs/examples/use_cases/webdataset-externalsource.ipynb

@@ -261,7 +261,7 @@
     "    \n",
     "    def webdataset_generator():\n",
     "        bytes_np_mapper = (lambda data: np.frombuffer(data, dtype=np.uint8),)*len(extensions)\n",
-    "        dataset_instance = (wds.WebDataset(paths, shardshuffle=False)\n",
+    "        dataset_instance = (wds.WebDataset(paths)\n",
     "                            .to_tuple(*extensions)\n",
     "                            .map_tuple(*bytes_np_mapper))\n",
     "        \n",

qa/TL0_jupyter/test_pytorch.sh

@@ -1,6 +1,6 @@
 #!/bin/bash -e
 # used pip packages
-pip_packages="pillow jupyter numpy matplotlib torch torchvision webdataset"
+pip_packages="pillow jupyter numpy matplotlib torch torchvision webdataset pyyaml"
 target_dir=./docs/examples
 
 test_body() {

qa/TL1_jupyter_conda/test_pytorch.sh

@@ -1,6 +1,6 @@
 #!/bin/bash -e
 # used pip packages
-pip_packages="pillow jupyter numpy matplotlib torch torchvision webdataset"
+pip_packages="pillow jupyter numpy matplotlib torch torchvision webdataset pyyaml"
 target_dir=./docs/examples
 
 # populate epilog and prolog with variants to enable/disable conda