Update sbt to 1.4.9 (#500)

scala-steward · web-flow · commit f60d0e046702 · 2021-03-12T08:48:00.000-08:00
diff --git a/project/build.properties b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.4.8
+sbt.version=1.4.9
