register watcher for new debugger type (#15141) (#15146)

Co-authored-by: Michael Lively <milively@microsoft.com>

src/notebooks/debugger/debuggerVariableRegistration.node.ts

@@ -23,6 +23,7 @@ export class DebuggerVariableRegistration implements IExtensionSyncActivationSer
     ) {}
     public activate() {
         this.disposables.push(this.debugService.registerDebugAdapterTrackerFactory(PYTHON_LANGUAGE, this));
+        this.disposables.push(this.debugService.registerDebugAdapterTrackerFactory('debugpy', this));
         this.disposables.push(this.debugService.registerDebugAdapterTrackerFactory(pythonKernelDebugAdapter, this));
         this.disposables.push(this.debugService.registerDebugAdapterTrackerFactory(pythonIWKernelDebugAdapter, this));
     }