Use more robust method to launch twine (#52)

Using the twine executable directly relies on the Python bin directory
being added to the path, which is not reliably the case in different
environments. I've created a new copy of the script since I'm iterating
very actively right now in the new wheels workflow. We can get rid of
the old script once I've verified that everything is working as
expected.

tools/rapids-twine-new

@@ -0,0 +1,57 @@
+#!/bin/bash
+# A utility script that wraps twine to upload all pip wheels of a workflow run
+# 
+# Positional Arguments:
+#   1) wheel name
+set -exou pipefail
+source rapids-constants
+export RAPIDS_SCRIPT_NAME="rapids-twine-new"
+
+if [ -z "$1" ]; then
+  rapids-echo-stderr "Must specify input arguments: WHEEL_NAME"
+  exit 1
+fi
+WHEEL_NAME="$1"
+
+WHEEL_SEARCH_KEY="wheel_python_${WHEEL_NAME}"
+
+WHEEL_DIR="./dist"
+mkdir -p "${WHEEL_DIR}"
+
+S3_PATH=$(rapids-s3-path)
+BUCKET_PREFIX=${S3_PATH/s3:\/\/${RAPIDS_DOWNLOADS_BUCKET}\//} # removes s3://rapids-downloads/ from s3://rapids-downloads/ci/rmm/...
+
+# shellcheck disable=SC2016
+WHEEL_TARBALLS=$(
+  set -eo pipefail;
+  aws \
+    --output json \
+    s3api list-objects \
+    --bucket "${RAPIDS_DOWNLOADS_BUCKET}" \
+    --prefix "${BUCKET_PREFIX}" \
+    --page-size 100 \
+    --query "Contents[?contains(Key, '${WHEEL_SEARCH_KEY}')].Key" \
+    | jq -c
+)
+export WHEEL_TARBALLS
+
+# first untar them all
+for OBJ in $(jq -nr 'env.WHEEL_TARBALLS | fromjson | .[]'); do
+  FILENAME=$(basename "${OBJ}")
+  S3_URI="${S3_PATH}${FILENAME}"
+
+  rapids-echo-stderr "Untarring ${S3_URI} into ${WHEEL_DIR}"
+  aws s3 cp --only-show-errors "${S3_URI}" - | tar xzf - -C "${WHEEL_DIR}"
+done
+
+# then run twine on all wheels
+export RAPIDS_RETRY_SLEEP=180
+# shellcheck disable=SC2086
+rapids-retry python -m twine \
+  upload \
+  --disable-progress-bar \
+  --non-interactive \
+  --skip-existing \
+  "${WHEEL_DIR}"/*.whl
+
+echo ""