[10.x] Introduce requireEnv helper

[lucasmichot]

It sometimes happens that we want to ensure that some environment variables are set, without relying on their default value, in case they are not found.

This is very much the case when working as a team with new joiners when setting up their Laravel project locally.

I believe it is valuable to have a way to defined if a given environment variable needs to be explicitly set.

This pull-request introduces the requireEnv() helper and the
\Illuminate\Support\Env::getRequired() method for this purpose.

They don't accept any default value, and an exception is thrown if the environment variable is not found.

---

Note:

The helper could also be named requiredEnv() (with a d), I don't have a strong opinion about this.

[lucasmichot]

The cheksuite is 🔴 because of some flaky tests:
cf. https://github.com/laravel/framework/actions/runs/6037421961/job/16381669035?pr=48261#step:9:171

[rojtjo]

I really like this idea!

Only note I have is that requireEnv should be renamed to require_env to match the other framework helpers.

[ankurk91]

I don't see any global function introduced in this PR.
The commit message is confusing.
The commit message will become changelog in future.

[dennisprudlo]

@ankurk91 Taylor removed the global helper in his commit before merging: 10f3b13

The commit "Introduce requireEnv helper" does indeed adds a global function: 7b7dd6b

[CyberMullah]

@taylorotwell or @lucasmichot can you explain how it will be used with an example. Thanks

[rojtjo]

@hamidafghan

<?php

use Illuminate\Support\Env;

// config/app.php
return [
    'name' => Env::getOrFail('APP_NAME'),
];