Remove an unnecessary step when stopping the tunnel (#1102)

Task/Issue URL:
https://app.asana.com/0/1207603085593419/1208865941226621/f

iOS PR: duckduckgo/iOS#3639
macOS PR: duckduckgo/macos-browser#3608

What kind of version bump will this require?: Patch

## Description

Removes a duplicated step from the tunnel stop logic that was causing
some trouble in the logs.

Sources/NetworkProtection/PacketTunnelProvider.swift

@@ -887,6 +887,7 @@ open class PacketTunnelProvider: NEPacketTunnelProvider {
     @MainActor
     private func stopTunnel() async throws {
         connectionStatus = .disconnecting
+
         await stopMonitors()
         try await stopAdapter()
     }
@@ -895,10 +896,6 @@ open class PacketTunnelProvider: NEPacketTunnelProvider {
     private func stopAdapter() async throws {
         try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
             adapter.stop { [weak self] error in
-                if let self {
-                    self.handleAdapterStopped()
-                }
-
                 if let error {
                     self?.debugEvents.fire(error.networkProtectionError)
 
@@ -1420,11 +1417,6 @@ open class PacketTunnelProvider: NEPacketTunnelProvider {
         try await startMonitors(testImmediately: testImmediately)
     }
 
-    @MainActor
-    public func handleAdapterStopped() {
-        connectionStatus = .disconnected
-    }
-
     // MARK: - Monitors
 
     private func startTunnelFailureMonitor() async {