Add Magento 2.4.8 compatibility via Monolog 3.x support

[mohaelmrabet]

Magento 2.4.8 requires Monolog 3.x, which introduces breaking changes: log level constants now return Level enum instead of integers.

Changes

• composer.json: Extend monolog constraint to ^2.0 || ^3.0
• StdoutHandler: Use integer log levels directly (compatible with both versions)
• LogLevel source model: Runtime detection via class_exists(Level::class) to access enum values in Monolog 3.x

// Monolog 3.x
['value' => Level::Debug->value, 'label' => __('DEBUG')]

// Monolog 2.x fallback
['value' => Logger::DEBUG, 'label' => __('DEBUG')]

Compatibility

Magento	Monolog
2.4.6-2.4.7	2.x ✓
2.4.8	3.x ✓

Also fixes incorrect config path in test (general/logging/log_level vs log_stream_settings/logging/log_level).

[Copilot]

Pull request overview

This PR adds Magento 2.4.8 compatibility by supporting Monolog 3.x, which introduces breaking changes where log level constants return Level enum objects instead of integers. The implementation uses a backward-compatible approach that works with both Monolog 2.x (used in Magento 2.4.6-2.4.7) and Monolog 3.x (required for Magento 2.4.8).

Key changes:

• Extended Monolog dependency constraint to support both major versions (^2.0 || ^3.0)
• Implemented runtime detection in LogLevel source model to use enum values when available
• Refactored StdoutHandler and tests to use integer log levels directly for cross-version compatibility

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
composer.json	Updated monolog constraint to ^2.0 || ^3.0 for Magento 2.4.8 compatibility
src/Logger/StdoutHandler.php	Replaced Logger::INFO constant with integer value (200) for cross-version compatibility
src/Model/Config/Source/LogLevel.php	Added runtime detection with class_exists(Level::class) to support both Monolog 2.x constants and 3.x enum values
src/Test/Unit/Logger/StdoutHandlerTest.php	Updated to use hardcoded integer log levels and added helper method to extract values from both int and Level types; fixed incorrect config path
src/Test/Unit/Model/Config/Source/LogLevelTest.php	Replaced Monolog constant references with hardcoded integer values for version-independent testing
README.md	Updated version badge to reflect support for Magento 2.4.6 through 2.4.8
CHANGELOG.md	Documented Monolog 3.x support and backward compatibility changes

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[Copilot]

The test expects plain string labels (e.g., 'label' => 'DEBUG') but the actual LogLevel::toOptionArray() method returns Phrase objects via __('DEBUG'). This assertion will fail because Phrase objects don't equal strings directly.

The test should either:

1. Use ->getText() on the labels before comparison, or
2. Expect Phrase objects in the expected array

Example fix:

$expectedOptions = [
    ['value' => 100, 'label' => __('DEBUG')],
    // ... etc
];

Suggested change

	['value' => 100, 'label' => 'DEBUG'],
	['value' => 200, 'label' => 'INFO'],
	['value' => 250, 'label' => 'NOTICE'],
	['value' => 300, 'label' => 'WARNING'],
	['value' => 400, 'label' => 'ERROR'],
	['value' => 500, 'label' => 'CRITICAL'],
	['value' => 550, 'label' => 'ALERT'],
	['value' => 600, 'label' => 'EMERGENCY'],
	['value' => 100, 'label' => __('DEBUG')],
	['value' => 200, 'label' => __('INFO')],
	['value' => 250, 'label' => __('NOTICE')],
	['value' => 300, 'label' => __('WARNING')],
	['value' => 400, 'label' => __('ERROR')],
	['value' => 500, 'label' => __('CRITICAL')],
	['value' => 550, 'label' => __('ALERT')],
	['value' => 600, 'label' => __('EMERGENCY')],