Update sttp:core to 1.5.9 (#21)

Updates com.softwaremill.sttp:core from 1.5.8 to 1.5.9.

I'll automatically update this PR to resolve conflicts as long as you don't change it yourself.

If you'd like to skip this version, you can just close this PR. If you have any feedback, just mention @scala-steward in the comments below.

Have a nice day!

build.sbt

@@ -18,7 +18,7 @@ val h2Version                  = "1.4.197"
 val log4CatsVersion            = "0.2.0"
 val http4sVersion              = "0.20.0-M5"
 val circeVersion               = "0.11.1"
-val sttpVersion                = "1.5.8"
+val sttpVersion                = "1.5.9"
 
 inThisBuild(
   List(