Add fix to prevent panic when ctx closed

If the context is closed, and that is the error that is received by the
dispose method, then that would elude to the fact that the iteration
has ended. Therefore, we shouldn't need to panic or log an error at
this point, and instead just continue on as normal. The page has closed
well before this panic occurs.

common/js_handle.go

@@ -2,6 +2,7 @@ package common
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"github.com/grafana/xk6-browser/k6ext"
@@ -79,7 +80,13 @@ func (h *BaseJSHandle) AsElement() *ElementHandle {
 // Dispose releases the remote object.
 func (h *BaseJSHandle) Dispose() {
 	if err := h.dispose(); err != nil {
-		k6ext.Panic(h.ctx, "dispose: %w", err)
+		// We do not want to panic on an error when the error is a closed
+		// context. The reason the context would be closed is due to the
+		// iteration ending and therefore the associated browser and its assets
+		// will be automatically deleted.
+		if !errors.Is(err, context.Canceled) {
+			k6ext.Panic(h.ctx, "dispose: %w", err)
+		}
 	}
 }