compilation errors every time a new version of firebase is used

I'm sorry if this issue doesn't actually have anything to do with Angularfire, and if it looks more like a question than an actual issue.
Feel free to close this issue if you feel it doesn't belong here.

I use yarn and have configured renovate bot on my project. So every time a new version of Firebase is released, it makes a commit which upgrades the version. And almost every time it does that (like in [this PR](https://github.com/jnizet/decouvertes-nature/pull/282), which upgrades from firebase 9.8.4 to firebase 9.9.0), the code, which compiled fine before, dosn't compile anymore, with errors such as the following one:

```
Error: Error: src/app/activity/activity.service.ts:185:5 - error TS2322: Type 'Observable<(string | FieldValue)[]>' is not assignable to type 'Observable'.
Type '(string | FieldValue)[]' is not assignable to type 'string[]'.
Type 'string | FieldValue' is not assignable to type 'string'.
Type 'FieldValue' is not assignable to type 'string'.
185 return collectionData(this.animatorCollection).pipe(
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
186 first(),
~~~~~~~~~~~~~~
...
193 )
~~~~~~~
194 );
```

for code looking like

```ts
export interface Animator {
name: string;
}

// ...
private animatorCollection: CollectionReference;
// ...
suggestAnimators(text: string): Observable> {
const query = text.toLowerCase();
return collectionData(this.animatorCollection).pipe(
first(),
map(animators =>
animators
.filter(a => a.name.toLowerCase().includes(query))
.map(a => a.name)
.sort()
.slice(0, 10)
)
);
}
```

So suddenly, for a reason that I ignore, the compiler doesn't infer the types correctly.

The fix is relatively simple: delete the yarn.lock file, and run yarn again.

But I wonder what I should do to avoid having to do that every time, and would like to understand why this strange behavior happens.

從 src/app/activity/activity.service.ts 開始，在保留 yarn.lock 的情況下升級 Firebase，以重現編譯錯誤。比較刪除 yarn.lock 前後的相依性解析結果，然後判斷相容的相依性行為或所需的專案變更，讓範例在 Firebase 升級後能夠一致地編譯。

由索引模型根據 Issue 內容生成。