Update URL for riscv_boostrap.sh file. (#19432)

Progress on https://github.com/iree-org/iree/issues/18518.

skip-ci: not tested by CI
diff --git a/build_tools/riscv/riscv_bootstrap.sh b/build_tools/riscv/riscv_bootstrap.sh
index fe7ca0f..f3e01c4 100755
--- a/build_tools/riscv/riscv_bootstrap.sh
+++ b/build_tools/riscv/riscv_bootstrap.sh
@@ -12,7 +12,7 @@
 set -o pipefail
 
 PREBUILT_DIR="${HOME}/riscv"
-IREE_ARTIFACT_URL="https://storage.googleapis.com/iree-shared-files"
+IREE_ARTIFACT_URL="https://sharkpublic.blob.core.windows.net/sharkpublic/GCP-Migration-Files"
 
 read -p "Enter the riscv tools root path(press enter to use default path:${PREBUILT_DIR}): " INPUT_PATH
 if [[ "${INPUT_PATH}" ]]; then