Update scalafmt-core to 3.8.4 (#111)

Co-authored-by: horothesun-scala-steward[bot] <132169906+horothesun-scala-steward[bot]@users.noreply.github.com>

Author: horothesun-scala-steward[bot]

.scalafmt.conf

@@ -1,4 +1,4 @@
-version = 3.8.3
+version = 3.8.4
 runner.dialect = scala213
 align.preset = more
 maxColumn = 120