Change pytest distribution algorithm and increase parallelism in CI (#…

…10232)

This PR increases the number of cores allocated to `pytest-xdist` and also changes distribution algorithm for `cudf` to `loadscope`.

This PR:
```
custreamz:
= 600 passed, 6 skipped, 145 xfailed, 96 xpassed, 7 warnings in 88.10s (0:01:28) =

dask-cudf:
= 891 passed, 13 skipped, 2 xfailed, 1 xpassed, 115 warnings in 63.42s (0:01:03) =

cudf(loadscope):
= 88743 passed, 2408 skipped, 985 xfailed, 1978 xpassed, 3115 warnings in 1195.87s (0:19:55) =
```

`branch-22.04`:

```

custreamz:

= 600 passed, 6 skipped, 145 xfailed, 96 xpassed, 5 warnings in 102.16s (0:01:42) =

dask-cudf:

= 891 passed, 13 skipped, 2 xfailed, 1 xpassed, 113 warnings in 78.00s (0:01:18) =

cudf:

= 88745 passed, 2408 skipped, 985 xfailed, 1978 xpassed, 3113 warnings in 2249.52s (0:37:29) =
```

Authors:
  - GALI PREM SAGAR (https://github.com/galipremsagar)

Approvers:
  - Jordan Jacobelli (https://github.com/Ethyling)
  - Bradley Dice (https://github.com/bdice)

URL: #10232

ci/gpu/build.sh

@@ -249,15 +249,15 @@ fi
 
 cd "$WORKSPACE/python/cudf"
 gpuci_logger "Python py.test for cuDF"
-py.test -n 6 --cache-clear --basetemp="$WORKSPACE/cudf-cuda-tmp" --ignore="$WORKSPACE/python/cudf/cudf/benchmarks" --junitxml="$WORKSPACE/junit-cudf.xml" -v --cov-config=.coveragerc --cov=cudf --cov-report=xml:"$WORKSPACE/python/cudf/cudf-coverage.xml" --cov-report term
+py.test -n 8 --cache-clear --basetemp="$WORKSPACE/cudf-cuda-tmp" --ignore="$WORKSPACE/python/cudf/cudf/benchmarks" --junitxml="$WORKSPACE/junit-cudf.xml" -v --cov-config=.coveragerc --cov=cudf --cov-report=xml:"$WORKSPACE/python/cudf/cudf-coverage.xml" --cov-report term --dist=loadscope
 
 cd "$WORKSPACE/python/dask_cudf"
 gpuci_logger "Python py.test for dask-cudf"
-py.test -n 6 --cache-clear --basetemp="$WORKSPACE/dask-cudf-cuda-tmp" --junitxml="$WORKSPACE/junit-dask-cudf.xml" -v --cov-config=.coveragerc --cov=dask_cudf --cov-report=xml:"$WORKSPACE/python/dask_cudf/dask-cudf-coverage.xml" --cov-report term
+py.test -n 8 --cache-clear --basetemp="$WORKSPACE/dask-cudf-cuda-tmp" --junitxml="$WORKSPACE/junit-dask-cudf.xml" -v --cov-config=.coveragerc --cov=dask_cudf --cov-report=xml:"$WORKSPACE/python/dask_cudf/dask-cudf-coverage.xml" --cov-report term
 
 cd "$WORKSPACE/python/custreamz"
 gpuci_logger "Python py.test for cuStreamz"
-py.test -n 6 --cache-clear --basetemp="$WORKSPACE/custreamz-cuda-tmp" --junitxml="$WORKSPACE/junit-custreamz.xml" -v --cov-config=.coveragerc --cov=custreamz --cov-report=xml:"$WORKSPACE/python/custreamz/custreamz-coverage.xml" --cov-report term
+py.test -n 8 --cache-clear --basetemp="$WORKSPACE/custreamz-cuda-tmp" --junitxml="$WORKSPACE/junit-custreamz.xml" -v --cov-config=.coveragerc --cov=custreamz --cov-report=xml:"$WORKSPACE/python/custreamz/custreamz-coverage.xml" --cov-report term
 
 gpuci_logger "Test notebooks"
 "$WORKSPACE/ci/gpu/test-notebooks.sh" 2>&1 | tee nbtest.log