♻️💄 simplify KorAPConnection class instantiations to modern syntax

Update all class instantiations from `new("KorAPConnection")` to `KorAPConnection()`.
This is possible with R >= 4.0.

Change-Id: I01131fb32045e084cafbb9e05cd8ba99f8f20f1b
diff --git a/man/clearAccessToken-KorAPConnection-method.Rd b/man/clearAccessToken-KorAPConnection-method.Rd
index 2dfa4b5..a6c665a 100644
--- a/man/clearAccessToken-KorAPConnection-method.Rd
+++ b/man/clearAccessToken-KorAPConnection-method.Rd
@@ -19,7 +19,7 @@
 \examples{
 
 \dontrun{
-kco <- new("KorAPConnection")
+kco <- KorAPConnection()
 kco <- clearAccessToken(kco)
 }