3.0.0

This is mostly a cleanup release offering stronger type guarantees for integrators with the
array->object/enum changes, but there is no big new feature for end users.

See UPGRADE notes for details on all breaking changes especially if you are extending/implementing Monolog classes/interfaces.

Noteworthy BC Breaks:

• The minimum supported PHP version is now 8.1.0.
• Log records have been converted from an array to a Monolog\LogRecord object
  with public (and mostly readonly) properties. e.g. instead of doing
  $record['context'] use $record->context.
  In formatters or handlers if you rather need an array to work with you can use $record->toArray()
  to get back a Monolog 1/2 style record array. This will contain the enum values instead of enum cases
  in the level and level_name keys to be more backwards compatible and use simpler data types.
• FormatterInterface, HandlerInterface, ProcessorInterface, etc. changed to contain LogRecord $record
  instead of array $record parameter types. If you want to support multiple Monolog versions this should
  be possible by type-hinting nothing, or array|LogRecord if you support PHP 8.0+. You can then code
  against the $record using Monolog 2 style as LogRecord implements ArrayAccess for BC.
  The interfaces do not require a LogRecord return type even where it would be applicable, but if you only
  support Monolog 3 in integration code I would recommend you use LogRecord return types wherever fitting
  to ensure forward compatibility as it may be added in Monolog 4.
• Log levels are now stored as an enum Monolog\Level
• Removed deprecated SwiftMailerHandler, migrate to SymfonyMailerHandler instead.
• ResettableInterface::reset() now requires a void return type.
• All properties have had types added, which may require you to do so as well if you extended
  a Monolog class and declared the same property.

New deprecations:

• Logger::DEBUG, Logger::ERROR, etc. are now deprecated in favor of the Monolog\Level enum.
  e.g. instead of Logger::WARNING use Level::Warning if you need to pass the enum case
  to Monolog or one of its handlers, or Level::Warning->value if you need the integer
  value equal to what Logger::WARNING was giving you.
• Logger::getLevelName() is now deprecated.