bug(cdk/menu): menu is closed on mousedown event

### Is this a regression?

- [X] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

14

### Description

When menu is opened, using standalone trigger, it is closed by clicking outside the menu on mousedown event.

### Reproduction

1. Go to the CDK menu examples page: https://material.angular.io/cdk/menu/examples.
2. Open the menu using "Click me!" button under "Menu with Standalone Trigger".
3. Click outside the menu.

### Expected Behavior

Menu should be closed using mouseup event to comply with WCAG Level A - 2.5.2 criterion (https://www.w3.org/TR/WCAG21/#pointer-cancellation)

### Actual Behavior

Menu is closed with mousedown event.
The same bahavior appears in CDK v15 - https://v15.material.angular.io/cdk/menu/examples
But not in v14 - https://v14.material.angular.io/cdk/menu/examples

Also latest Material Menu component works as expected - https://material.angular.io/components/menu/examples

### Environment

- Angular: 15, 16
- CDK/Material: 15, 16
- Browser(s): latest Chrome, Firefox, Safari
- Operating System (e.g. Windows, macOS, Ubuntu): macOS (14.0 and 13.6)

Das Issue verweist auf die CDK-Menübeispielseite und ihr standalone-trigger-Beispiel. Reproduziere zunächst das outside-click-Verhalten und verfolge anschließend die Ereignisbehandlung des CDK-Menüs. Als abgeschlossen gilt die Aufgabe, wenn das Menü bei mouseup statt bei mousedown geschlossen wird, entsprechend dem erwarteten WCAG-Verhalten zur Pointer-Cancellation und den funktionierenden v14- und Material-Menübeispielen.

Vom Indexierungsmodell aus dem Issue-Text verfasst.