Alias environment files not read on pre-deploy checks

### [REQUIRED] Environment info

**firebase-tools:** 10.9.0

**Platform:** macOS
### [REQUIRED] Test case

See below.

### [REQUIRED] Steps to reproduce

Firebase aliases:
```js
// .firebaserc
{
"projects": {
"prod": "",
"dev": "",
"default": ""
},
...
}
```

.env variables:
```txt
// ./functions/.env

// ./functions/.env.prod
FB={"private-rtdb": "-private", "public-rtdb": "-public"}
```

We have helper function that checks if the variable exists:
```ts
function getVariable(key: string) {
const { env } = process
console.log("Current variables", env)
// => Prints:
// "FIREBASE_CONFIG": ",
// "GCLOUD_PROJECT": "",
// "GOOGLE_CLOUD_QUOTA_PROJECT": "",
// "PORT": "8143",
// "FUNCTIONS_CONTROL_API": "true",
// "HOME": "MY HOME PATH FROM COMPUTER",
// "PATH": "",
// "NODE_ENV": "",
// "CLOUD_RUNTIME_CONFIG": "",
// "__CF_USER_TEXT_ENCODING": "..."

const [variableName, field] = key.split('.')

try {
const json = JSON.parse(env[variableName])
if (field) {
return json?.[field]
}
return json
} catch {
return env[variableName]
}
}
```

1. Use v1 function for Realtime Database
2. Specify function instance for the function from the env file:
```ts
import { getVariable } from './utils/variables.ts'

functions
.region('europe-west1')
.database.instance(getVariable('FB.private-rtdb'))
.ref('/test')
.onWrite(async (snapshot, context) => {...})
```
3. Now when deploying the function it fails as it cannot find the "FB" variable

So it seems that the `process.env` is read from the `.env` -file only, not from the aliased env like documentation states in [here](https://firebase.google.com/docs/functions/config-env?gen=1st#deploying_multiple_sets_of_environment_variables_2).

I did try with adding the `dotenv` node module and using `dotenv.config()` but there was no changes there.

### [REQUIRED] Expected behavior

Pre deploy checks should respect named `.env` files and list the variables.

### [REQUIRED] Actual behavior
See above.

### Final comment
We did got around this issue with the `CLOUD_RUNTIME_CONFIG` variable, which did included correct env variables. But I assume it is a deprecated variable that `runtimeconfig` sets. So if that is removed in the future, we will end up with the same block.