Update sbt to 1.5.7 (#427)

scala-steward · web-flow · commit 630e3c7d15d8 · 2021-12-16T07:59:09.000+01:00
diff --git a/project/build.properties b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.5.5
+sbt.version=1.5.7
