cmd/tsconnect: update device authorization copy

"Device Authorization" was recently renamed to "Device Approval"
on the control side. This change updates tsconnect to match.

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>

cmd/tsconnect/src/app/header.tsx

@@ -30,7 +30,7 @@ const STATE_LABELS = {
   NoState: "Initializing…",
   InUseOtherUser: "In-use by another user",
   NeedsLogin: "Needs login",
-  NeedsMachineAuth: "Needs authorization",
+  NeedsMachineAuth: "Needs approval",
   Stopped: "Stopped",
   Starting: "Starting…",
   Running: "Running",