chore(NODE-6488): specify target=es2021 for ts compilation tests (#4303)

.evergreen/run-typescript.sh

@@ -44,8 +44,12 @@ if [ "$TS_CHECK" == "COMPILE_DRIVER" ]; then
     npm run build:ts
 elif [ "$TS_CHECK" == "CHECK_TYPES" ]; then
     echo "checking driver types"
+    if [ "$TS_VERSION" == "4.4" ]; then
     # check compilation
-    node $TSC mongodb.d.ts
+        node $TSC mongodb.d.ts --module commonjs --target es2021
+    else
+    node $TSC mongodb.d.ts --module node16 --target es2021
+    fi
 else
     "Invalid value $TS_CHECK for TS_CHECK environment variable."
     exit 1

README.md

@@ -99,6 +99,8 @@ This is the lowest typescript version guaranteed to work with our driver: older
 Since typescript [does not restrict breaking changes to major versions](https://github.com/Microsoft/TypeScript/wiki/Breaking-Changes), we consider this support best effort.
 If you run into any unexpected compiler failures against our supported TypeScript versions, please let us know by filing an issue on our [JIRA](https://jira.mongodb.org/browse/NODE).
 
+Additionally, our Typescript types are compatible with the ECMAScript standard for our minimum supported Node version.  Currently, our Typescript targets es2021.
+
 ## Installation
 
 The recommended way to get started using the Node.js 5.x driver is by using the `npm` (Node Package Manager) to install the dependency in your project.