Fix extension installation test

This throws now that the exit is non-zero.

src/node/main.ts

@@ -52,12 +52,17 @@ export const runCodeCli = async (args: DefaultedArgs): Promise<void> => {
 
   try {
     await spawnCli(await toCodeArgs(args))
+    // Rather than have the caller handle errors and exit, spawnCli will exit
+    // itself.  Additionally, it does this on a timeout set to 0.  So, try
+    // waiting for VS Code to exit before giving up and doing it ourselves.
+    await new Promise((r) => setTimeout(r, 1000))
+    logger.warn("Code never exited")
+    process.exit(0)
   } catch (error: any) {
+    // spawnCli catches all errors, but just in case that changes.
     logger.error("Got error from Code", error)
     process.exit(1)
   }
-
-  process.exit(0)
 }
 
 export const openInExistingInstance = async (args: DefaultedArgs, socketPath: string): Promise<void> => {

test/integration/installExtension.test.ts

@@ -13,9 +13,10 @@ describe("--install-extension", () => {
   })
   it("should use EXTENSIONS_GALLERY when set", async () => {
     const extName = "author.extension"
-    const { stderr } = await runCodeServerCommand([...setupFlags, "--install-extension", extName], {
-      EXTENSIONS_GALLERY: "{}",
-    })
-    expect(stderr).toMatch("No extension gallery service configured")
+    await expect(
+      runCodeServerCommand([...setupFlags, "--install-extension", extName], {
+        EXTENSIONS_GALLERY: "{}",
+      }),
+    ).rejects.toThrow("No extension gallery service configured")
   })
 })