moveend is fired without a reason due to resize observer

[HarelM]

The following browser test fails as of version 3.0.0.pre.5:
It shows that moveend is fired before load on a map that doesn't move.
This is due to the change to ResizeObserver as it fire an event right after subsribing to it.
See #2157 for more info.

    test('No moveend before load', async () => {
        let loadWasFirst = await page.evaluate(() => {
            const map2 = new maplibregl.Map({
                container: 'map', // container id
                style: 'https://demotiles.maplibre.org/style.json', // style URL
                center: [10, 10], // starting position [lng, lat]
                zoom: 10 // starting zoom
            });
            return new Promise<boolean>((resolve, _reject) => {
                map2.once('moveend', () => resolve(false));
                map2.once('load', () => resolve(true));
            });
        });
        expect(loadWasFirst).toBeTruthy();
    }, 20000);