debug: fix edit watch expressions when no debug session is present

The commit fixes an issue where the edit watch expressions was not updated properly if there was no debug session present.

Signed-off-by: Sophia Li <sophia@ti.com>

Author: sophiali23

packages/debug/src/browser/view/debug-watch-expression.tsx

@@ -42,11 +42,10 @@ export class DebugWatchExpression extends ExpressionItem {
     }
 
     protected override setResult(body?: DebugProtocol.EvaluateResponse['body'], error?: string): void {
-        if (!this.options.session()) {
-            return;
+        if (this.options.session()) {
+            super.setResult(body, error);
+            this.isError = !!error;
         }
-        super.setResult(body, error);
-        this.isError = !!error;
         this.options.onDidChange();
     }