fix(cli-repl): clear window title when mongosh exits MONGOSH-1233

Terminals do not provide an easy way to "push/pop" window titles,
so we're basically stuck with clearing the window title when mongosh
exits on a best-effort basis.

When somebody brings this up as an issue, we should still recommend
them to include something in their shell's .rc file to automatically
reset window titles after each shell command.

Author: addaleax

packages/cli-repl/src/run.ts

@@ -346,6 +346,8 @@ function suppressExperimentalWarnings() {
 }
 
 function onExit(code?: number): never {
+  setTerminalWindowTitle(''); // Clear the terminal window title MONGOSH-1233
+
   // Node.js 20.0.0 made p.exit(undefined) behave as p.exit(0) rather than p.exit(): (code?: number | undefined): never => {
   try {
     try {