Disable VSCode persistent terminal sessions

Persistent sessions: `terminal.integrated.enablePersistentSessions`.
Yet another obnoxious "feature" that shouldn't be enabled by default.

https://code.visualstudio.com/docs/getstarted/settings
https://code.visualstudio.com/docs/editor/integrated-terminal
https://code.visualstudio.com/updates/v1_54
https://github.com/microsoft/vscode/search?q=label%3Aterminal-persistence&type=issues

Other integrated terminal fixes and "features" I've had to disable:

- Terminal tabs:
  - 23e32a2
  - 4813726
- Rearranging `$PATH`: 3ca8e2c
- Breaking forward delete word: a71fdc7

vscode/User/settings.json

@@ -58,8 +58,10 @@
   "telemetry.telemetryLevel": "off",
   "terminal.external.osxExec": "Terminal.app",
   "terminal.integrated.cursorStyle": "block",
+  "terminal.integrated.enablePersistentSessions": false,
   "terminal.integrated.fontSize": 12,
   "terminal.integrated.inheritEnv": false,
+  "terminal.integrated.persistentSessionReviveProcess": "never",
   "terminal.integrated.scrollback": 10000,
   "terminal.integrated.tabs.enabled": false,
   "update.mode": "manual",