4.0 | Make sure that everything which was deprecated in 3.x has been removed in 4.0

[jrfnl]

• 3.2.0: Old-style ignore annotation syntax
• 3.3.0: Old-style (comma-delimited string) setting of array properties
• 3.3.0: T_ARRAY_HINT Token
• 3.3.0: T_RETURN_TYPE Token
• 3.3.0: Squiz.WhiteSpace.LanguageConstructSpacing Sniff
• 3.4.0: Generic.Formatting.NoSpaceAfterCast Sniff
• 3.5.7: The new method of PHP 8.0 tokenizing for namespaced names has been reverted to the pre 8.0 method. This change will be removed in PHPCS 4.0 as the PHP 8.0 tokenizing method will be backported for pre 8.0 versions
• 3.8.0: The third parameter for the Ruleset::setSniffProperty() method has been changed to expect an array, Existing code will continue to work but will throw a deprecation error
• [3.9.0]: The complete MySource standard - Soft deprecate all sniffs which are to be removed in PHPCS 4.0 #276 + Remove MySource standard squizlabs/PHP_CodeSniffer#2471
• [3.9.0]: JS/CSS support + all JS/CSS specific sniffs - Soft deprecate all sniffs which are to be removed in PHPCS 4.0 #276 + Remove CSS and JS tokenizers + related sniffs squizlabs/PHP_CodeSniffer#2448
• [3.9.0]: ExactMatch::getBlacklist() and ExactMatch::getWhitelist() methods - see Filters/ExactMatch: deprecate getBlacklist() and getWhitelist() methods #198 and 4.0 | Filters/ExactMatch: remove getBlacklist() and getWhitelist() methods #199
• [3.9.0]: Zend.Debug.CodeAnalyzer - see Zend.Debug.CodeAnalyzer: soft deprecate the sniff #277 / 4.0 | Zend.Debug.CodeAnalyzer: remove sniff #58

[jrfnl]

Loosely related to #120