[11.x] Adds ServiceProvider::publishesMigrations() method

[nunomaduro]

This minimal pull request proposes the addition of a ServiceProvider::publishesMigrations() method, which can be used in favor of ServiceProvider::publishes() for migrations. It will ensure that any published migration has an "up-to-date" date in its name.

To get started, packages may opt in to this new method simply by replacing publishes with publishesMigrations:

        $this->publishes([
            __DIR__.'/../config/pennant.php' => config_path('pennant.php'),
        ], 'pennant-config');

-       $this->publishes([
+       $this->publishesMigrations([
            __DIR__.'/../database/migrations' => $this->app->databasePath('migrations'),
        ], 'pennant-migrations');

If a package wants to support multiple Laravel versions, you may use the method_exists function like so:

$migrations = [
    __DIR__.'/../database/migrations' => $this->app->databasePath('migrations'),
];

method_exists($this, 'publishesMigrations')
    ? $this->publishesMigrations($migrations, 'pennant-migrations')
    ? $this->publishes($migrations, 'pennant-migrations')

The result will be that, instead of publishing a migration with an old date, Laravel will use a new date instead:

-2015_11_01_000001_create_features_table.php
+2023_12_05_132339_create_features_table.php

Note, when a package contains multiple migrations, for example like Jetstream with create_user and create_team_user, the package developer needs to add a number after the date. Here is an example, before and after:

-2015_11_01_000001_create_features_table.php
+2023_12_05_132339_create_features_table.php

At the moment, and intentionally, because I wanted to ensure we discuss it before coding it, this pull request does not detect if the migration already exists. So, if you run the command php artisan vendor:publish --provider="Laravel\Pennant\PennantServiceProvider" twice, you will end up with two similar migrations in your database/migrations directory:

+2023_12_05_132339_create_features_table.php
+2023_12_05_132400_create_features_table.php // duplicated here...