Malformed protobuff after geojson-vt parsing.

Nobody has claimed this yet.

## Context

I'm trying to serve a dynamic vector tiles routes from MongoDB documents.

I have some data in a mongodb, which — after some complex query — I am aggregating into a GeoJSON feature collection that looks like this :
```json
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"properties": {
"_id": "63c9081b6826b11dce76b781",
"name": "Walsh - Romaguera"
},
"geometry": {
"type": "Point",
"coordinates": [
4.5988,
46.0235
]
}
},
{
"type": "Feature",
"properties": {
"_id": "63c9081b6826b11dce76b782",
"name": "McKenzie, Bashirian and Wintheiser"
},
"geometry": {
"type": "Point",
"coordinates": [
4.5777,
45.993
]
}
}
]
}
```

I'm building server side a tile index with `geojson-vt` like so :

```ts
import geojsonVt from 'geojson-vt'
export type GeoJSONVT = ReturnType

export const tileIndex: GeoJSONVT = geojsonVt(myFeatureCollection, {})
```

Later, in an express handler, I'm serving tiles like so :

```
import { tileIndex } from './tile-index.ts'
const vtpbf = require('vt-pbf')

const tilesHandler = (req, res) => {
const { z, x, y } = req.params

// Getting tile as json
const jsonTile = tileIndex.getTile(z, x, y)

// Converting tile to pbf
const pbfTile = jsonTile != null ? vtpbf.fromGeojsonVt({ geojsonLayer: jsonTile }) : null

res
.status(200)
.type('application/x-protobuf')
.send()
}
```

I bound this to a route like so
```ts
router.get('/:z/:x/:y.pbf', tilesHandler)
```

And am calling this in mapbox-gl (with react-map-gl) like so :
```tsx

```

------

## Issue

MapboxGL is complaining in frontend :
> Error {message: 'Unimplemented type: 3'}

Which obviously tells [pbf is malformed](https://github.com/mapbox/mapbox-gl-js/issues/1567)

Here are some logs :

jsonTile
```json
{
"features": [
{
"geometry": [
[
791,
1360
]
],
"type": 1,
"tags": {
"_id": "63c92f4b4b38c39b45d8c5ba",
"name": "Ryan and Sons"
}
},
{
"geometry": [
[
200,
2166
]
],
"type": 1,
"tags": {
"_id": "63c92f4b4b38c39b45d8c5bb",
"name": "Zieme Inc"
}
}
],
"numPoints": 2,
"numSimplified": 2,
"numFeatures": 2,
"source": [
{
"id": null,
"type": "Point",
"geometry": [
0.5128838888888889,
0.3557929645239258,
0
],
"tags": {
"_id": "63c92f4b4b38c39b45d8c5ba",
"name": "Ryan and Sons"
},
"minX": 0.5128838888888889,
"minY": 0.3557929645239258,
"maxX": 0.5128838888888889,
"maxY": 0.3557929645239258
},
{
"id": null,
"type": "Point",
"geometry": [
0.5127430555555555,
0.355985194665117,
0
],
"tags": {
"_id": "63c92f4b4b38c39b45d8c5bb",
"name": "Zieme Inc"
},
"minX": 0.5127430555555555,
"minY": 0.355985194665117,
"maxX": 0.5127430555555555,
"maxY": 0.355985194665117
}
],
"x": 525,
"y": 364,
"z": 10,
"transformed": true,
"minX": 0.5127430555555555,
"minY": 0.3557929645239258,
"maxX": 0.5128838888888889,
"maxY": 0.355985194665117
}
```

pbfTile
```bash
Uint8Array(96) [
26, 94, 120, 1, 10, 12, 103, 101, 111, 106, 115, 111,
110, 76, 97, 121, 101, 114, 40, 128, 32, 18, 15, 18,
4, 0, 0, 1, 1, 24, 1, 34, 5, 9, 220, 24,
192, 42, 26, 3, 95, 105, 100, 26, 4, 110, 97, 109,
101, 34, 28, 10, 26, 34, 54, 51, 99, 57, 50, 102,
52, 98, 52, 98, 51, 56, 99, 51, 57, 98, 52, 53,
100, 56, 99, 53, 98, 97, 34, 34, 15, 10, 13, 82,
121, 97, 110, 32, 97, 110, 100, 32, 83, 111, 110, 115
]
```

Start in the shown tilesHandler, following the result of vtpbf.fromGeojsonVt through the Express response path. Reproduce the request with the sample geojson-vt tile and inspect the bytes received by the client. Done means the response contains the generated vector-tile bytes and Mapbox GL can parse the tile without the protobuf error.

Written by the indexing model from the issue text.