Simplify FactoryImmutable::getInstance

Update PHPDoc

Fix #2945

Allow to pass Unit enum for unit name

Make a meaningful translation in fa.php (Persian)

Use static values for enums until dropping PHP 8.1

Allow only callable or null for macro value

Record mixin object methods only if they return callable

Allow to remove macro by passing null value

# Conflicts:
# .github/workflows/tests.yml
# phpstan.neon

Remove `null` from `parse` and `rawParse` return types

Use PHPUnit attributes

Merge Windows and Ubuntu tests into a single matrix

Enable Laravel 11 check

Fix short year Ukrainian plural

Replace $tz with $timezone

Aligning argument name with native DateTime __construct, createFromFormat, etc.

Fix #2790

Fix fallback from setter to macro

# Conflicts:
# src/Carbon/CarbonPeriod.php
# tests/Carbon/StringsTest.php
# tests/CarbonImmutabl...

Fix typos

Isolate factories

Use febr. as Hungarian abbreviation for február (February)

Consider same "month" only in the same year

Fix #2910

Remove default interval from toIso8601String output

Fix typo of day name in Slovak language

Implement WeekDay, Month and Unit enums