Update @vscode/test-web for integration test stability fix (#847)

Contains a fix for
microsoft/vscode-test-web#106 . I see at least
one 504 error in main in the last couple of weeks, so this should
improve stability.

I'll continue to monitor the integration tests after this and reenable
them on PRs if they're stable.

package.json

@@ -26,7 +26,7 @@
     "@vscode/debugadapter": "^1.63.0",
     "@vscode/debugprotocol": "^1.63.0",
     "@vscode/extension-telemetry": "^0.8.5",
-    "@vscode/test-web": "^0.0.47",
+    "@vscode/test-web": "^0.0.48",
     "chai": "^4.3.10",
     "esbuild": "^0.19.5",
     "eslint": "^8.51.0",