fix: load test extension onStartupFinished

The extension needs to be loaded as soon as VS Code is loaded.
Otherwise, it's likely the e2e test will fail.

Author: jsjoeio

test/e2e/extensions/test-extension/package.json

@@ -4,7 +4,7 @@
   "version": "0.0.1",
   "publisher": "coder",
   "activationEvents": [
-    "onCommand:codeServerTest.proxyUri"
+    "onStartupFinished"
   ],
   "engines": {
     "vscode": "^1.56.0"
@@ -26,4 +26,4 @@
   "scripts": {
     "build": "tsc"
   }
-}
+}