[6.x] Resolve method templates for polymorphic array callables

[alies-dev]

Fixes #6549.

Passing [Class::class, 'method'] to a specialised callable parameter used to trip InvalidArgument when the method was templated, because the method's @template atoms were carried into the callable unchanged and nothing would later match int against B.

Before / after

class Id {
    /** @template B @param B $b @return B */
    public static function id($b) { return $b; }
}

/** @param callable(int): int $f */
function bar(callable $f): int { return $f(1); }

bar([Id::class, 'id']);

Before: InvalidArgument — callable(int): int vs callable(B as mixed): B as mixed.
After: accepted, B is inferred as int from the container.

What changed

In CallableTypeComparator::getCallableFromAtomic, the TKeyedArray branch now wraps the built callable in a Union and runs fillTemplateResult + TemplateInferredTypeReplacer::replace against the container callable — the same idiom the invokable-class branch below already uses. The template walker handles param/return variance and falls unmatched templates back to their declared bounds, so nothing leaks.

Guarded on template_types !== null && container_type_part !== null, so callers that don't supply a container (e.g. ClosureFromCallableReturnTypeProvider, ScalarTypeComparator) are untouched.

---

Note

Medium Risk
Changes callable type construction for array-callables to resolve method-level templates using the expected callable signature, which can affect type-checking outcomes across projects using templated methods as callables.

Overview
Fixes handling of templated methods used as array callables (e.g. [Class::class, "method"]) by resolving method-level templates against the expected callable type when building a TCallable in CallableTypeComparator::getCallableFromAtomic.

Adds coverage for polymorphic static/instance/multi-template array callables (including array_map) and a negative test ensuring mismatched expected return types still raise InvalidArgument.

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