ci(NODE-5345): add guards to install_dependencies for necessary env variables (#3713)

Author: baileympearson

.evergreen/install-dependencies.sh

@@ -5,6 +5,9 @@ NODE_LTS_VERSION=${NODE_LTS_VERSION:-14}
 
 source "${PROJECT_DIRECTORY}/.evergreen/init-node-and-npm-env.sh"
 
+if [[ -z "${npm_global_prefix}" ]]; then echo "npm_global_prefix is unset" && exit 1; fi
+if [[ -z "${NODE_ARTIFACTS_PATH}" ]]; then echo "NODE_ARTIFACTS_PATH is unset" && exit 1; fi
+
 CURL_FLAGS=(
   --fail          # Exit code 1 if request fails
   --compressed    # Request a compressed response should keep fetching fast
@@ -90,9 +93,6 @@ else
   mv "${NODE_ARTIFACTS_PATH}/${node_directory}" "${NODE_ARTIFACTS_PATH}/nodejs"
 fi
 
-export PATH="$NODE_ARTIFACTS_PATH/npm_global/bin:$NODE_ARTIFACTS_PATH/nodejs/bin:$PATH"
-hash -r
-
 if [[ $operating_system != "win" ]]; then
   # Update npm to latest when we can
   npm install --global npm@latest