Improve PHP 8.5 pipe operator formatting

[apeschar]

Summary

• classify PHP 8.5's T_PIPE as an operator so spaces are added around |>
• preserve input newlines before pipe operators, including with operators-first and operators-last modes
• register the pipe operator's left associativity and precedence between concatenation and comparison
• add a focused regression test and update existing PHP 8.5 fixtures and generated documentation

Current main turns:

$result = $value
    |> first(...)
    |> second(...);

into:

$result = $value|> first(...)|> second(...);

With this change, multiline chains retain their layout and inline expressions become $value |> first(...) |> second(...).

Validation

• PHP 8.2: 7,885 tests, 23,715 assertions
• PHP 8.4: 8,072 tests, 24,287 assertions
• PHP 8.5: 8,129 tests, 24,458 assertions
• PHPStan on PHP 8.4
• generated-file check
• PHP CS Fixer and pretty-php checks
• PHAR build and smoke test