Ensure we set the AWS region. (#19178)

This fix was found by Benjy in #18088 and here it just gets applied in
a missed spot.

build-support/bin/create_s3_index_file.sh

@@ -9,19 +9,25 @@ fi
 
 set -euox pipefail
 
+REGION=us-east-1
+
+function aws_s3() {
+  aws --region="${REGION}" s3 "$@"
+}
+
 SHA=$1
 WHEEL_DIR=binaries.pantsbuild.org/wheels/pantsbuild.pants
 
-VERSION=$(aws s3 ls "s3://${WHEEL_DIR}/${SHA}/" | awk '{print $2}' | tr -d "/")
+VERSION=$(aws_s3 ls "s3://${WHEEL_DIR}/${SHA}/" | awk '{print $2}' | tr -d "/")
 
 VERSION_DIR="${WHEEL_DIR}/${SHA}/${VERSION}"
 
-for obj in $(aws s3 ls "s3://${VERSION_DIR}/" | grep "\.whl" | awk '{print $4}'); do
+for obj in $(aws_s3 ls "s3://${VERSION_DIR}/" | grep "\.whl" | awk '{print $4}'); do
   URL="https://${VERSION_DIR}/${obj}"
   # Note that we replace the + with its escape sequence, as a raw + in a URL is
   # interpreted as a space.
   # Note also that we disable the shellcheck "echo may not expand escape sequences"
   # check, since in this case we don't want to expand escape sequences.
   # shellcheck disable=SC2028
   echo "<br><a href=\"${URL//+/%2B}\">${obj}</a>\n"
-done | aws s3 cp --acl=public-read --content-type=text/html - "s3://${VERSION_DIR}/index.html"
+done | aws_s3 cp --acl=public-read --content-type=text/html - "s3://${VERSION_DIR}/index.html"