Add symplify/monorepo-builder as dev dependency (#175)

This PR adds `symplify/monorepo-builder` as a development dependency to
the root `composer.json` file and updates the `composer.lock`
accordingly.

## Background

The repository already contains a `monorepo-builder.php` configuration
file that imports and uses classes from the `Symplify\MonorepoBuilder`
namespace:

```php
use Symplify\MonorepoBuilder\Config\MBConfig;
use Symplify\MonorepoBuilder\Release\ReleaseWorker\AddTagToChangelogReleaseWorker;
// ... other MonorepoBuilder imports
```

However, the `symplify/monorepo-builder` package was not declared as a
dependency in `composer.json`, which would cause issues when trying to
use the monorepo-builder functionality.

## Changes

- Added `"symplify/monorepo-builder": "^9.4"` to the `require-dev`
section of `composer.json`
- Updated `composer.lock` to include the new dependency (version 9.4.70)

## Compatibility

Version 9.4 was chosen for compatibility with the existing dependency
constraints in the project, particularly `sebastian/diff` which is
locked to version 4.x in the current setup. The newer 12.x versions of
monorepo-builder require `sebastian/diff ^6.0 || ^7.0`, which would
conflict with existing dependencies.

This change ensures that the monorepo-builder configuration can be
properly utilized without missing dependency errors.

> [!WARNING]
>
> <details>
> <summary>Firewall rules blocked me from connecting to one or more
addresses (expand for details)</summary>
>
> #### I tried to connect to the following addresses, but was blocked by
firewall rules:
>
> -
`https://api.github.com/repos/PHPCSStandards/PHP_CodeSniffer/zipball/8da41e9a9fe4cc14d23cf7fcef3b80476f54e511`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/PHPCSStandards/composer-installer/zipball/e9cf5e4bbf7eeaf9ef5db34938942602838fc2b1`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/PHPCompatibility/PHPCompatibility/zipball/9fb324479acf6f39452e0655d2429cc0d3914243`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/doctrine/instantiator/zipball/0daa7cfba7b009aa3c95ae585322fb596a4ca2ae`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/myclabs/DeepCopy/zipball/07d290f0c47959fd5eed98c95ee5602db07e0b6a`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/phar-io/manifest/zipball/65f90285728eae4eae313b8b6ba11b2f5436038e`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/phar-io/version/zipball/4f7fd7836c6f332bb2933569e566a0d6c4cbed74`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
> -
`https://api.github.com/repos/phpstan/phpstan/zipball/fcf8b71aeab4e1a1131d1783cef97b23a51b87a9`
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/KlQ2wK
/usr/bin/composer install --no-interaction` (http block)
> - Triggering command: `/usr/bin/php8.3 -n -c /tmp/NHYxIQ
/usr/bin/composer require --dev symplify/monorepo-builder:^9.4
--no-interaction --no-scripts` (http block)
>
> If you need me to access, download, or install something from one of
these locations, you can either:
>
> - Configure [Actions setup
steps](https://gh.io/copilot/actions-setup-steps) to set up my
environment, which run before the firewall is enabled
> - Add the appropriate URLs or hosts to the custom allowlist in this
repository's [Copilot coding agent
settings](https://github.com/WordPress/php-toolkit/settings/copilot/coding_agent)
(admins only)
>
> </details>



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Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: adamziel <[email protected]>

Author: Copilot

composer.json

@@ -29,7 +29,8 @@
         "slevomat/coding-standard": "^8.21.1",
         "wp-coding-standards/wpcs": "^3.2.0",
         "phpunit/phpunit": "^9.5",
-        "phpstan/phpstan": "^1.0"
+        "phpstan/phpstan": "^1.0",
+        "symplify/monorepo-builder": "^9.4"
     },
     "autoload": {
         "exclude-from-classmap": [