PackratParsers#phrase - different behaviour in Scala 2 vs Scala 3

[ilya-klyuchnikov]

• Repro/Test: https://github.com/ilya-klyuchnikov/scala-parser-combinators/commit/92a338ea19567614d30b1f6f1b8b7953849779a5
• It's OK for Scala 2.x, but fails for Scala 3.x - https://github.com/ilya-klyuchnikov/scala-parser-combinators/runs/2292531311