chore(NODE-5594): pin npm version

Author: W-A-James

.evergreen/install-dependencies.sh

@@ -95,8 +95,8 @@ else
 fi
 
 if [[ $operating_system != "win" ]]; then
-  # Update npm to latest when we can
-  npm install --global npm@latest
+  # pin npm to v9
+  npm install --global npm@9
   hash -r
 fi