etc: Add debugger.Terminate() to lldb_batchmode.py

Right now on the most recent version of LLDB installed on OSX we'll segfault on
all the LLDB tests if this isn't called (unfortunately). Hopefully we've updated
LLDB on the bots to actually get this working everywhere!

Closes #32994

Author: alexcrichton

src/etc/lldb_batchmode.py

@@ -216,4 +216,5 @@ def watchdog():
     print("Aborting.", file=sys.stderr)
     sys.exit(1)
 finally:
+    debugger.Terminate()
     script_file.close()