Improve font-locking and indentation in 'php-ts-mode'

Improve font-locking and indentation in 'php-ts-mode'

* lisp/progmodes/php-ts-mode.el (php-ts-mode--language-source-alist):
Updated to latest version of PHP grammar.
(php-ts-mode--indent-styles): 'namespace_use_declaration' is now
correctly indented.
(php-ts-mode--operators): Support of the "argument unpacking
operator".
(php-ts-mode--font-lock-settings): 'nullsafe_member_call_expression'
is now highlighted correctly.
(php-ts-mode--comment-indent-new-line): Delete trailing whitespace
before inserting newline (see bug#73900 for more information).
Bug#74239