Add PHP 8.2 DNF type support ((A&B)|C)

[TomasVotruba]

Problem

Disjunctive Normal Form types (PHP 8.2) were not parsed. A parenthesized intersection inside a union, e.g.

public function run((Countable&Traversable)|array $items) {}

failed with unexpected '(', expecting T_VARIABLE.

Change

• Grammar (internal/php8/php8.y): a parenthesized intersection '(' intersection_type ')' is now accepted as a union member, in the four combinations ((A&B)|C, C|(A&B), (A&B)|(C&D), and appended to a longer union). Adds zero new goyacc conflicts (baseline 3 shift/reduce, 7 reduce/reduce, unchanged).
• AST (pkg/ast/node.go): Intersection gains OpenParenthesisTkn / CloseParenthesisTkn, set only when the intersection is parenthesized.
• Printer: emits the parentheses when present, so DNF types round-trip unchanged.
• Regenerated php8.go via goyacc.
• Fixed the stale github.com/TomasVotruba/reco imports in php8.y left from the module extraction, so regeneration yields the correct module path.
• Added internal/php8/dnf_types_test.go (parameter, return, two parenthesized intersections, and print-back-unchanged).

Verification

Full suite and golangci-lint pass. With reco pointed at this branch, a type-coverage scan of symfony/console drops from 3 unparseable files to 1 (the remaining one is an unrelated attribute-position gap).