Update plugin org.jetbrains.kotlin.multiplatform to v2.0.21 (#37)

renovate[bot] · web-flow · commit f34a4e64f919 · 2024-10-10T14:11:58.000+02:00
Co-authored-by: renovate[bot] &lt;29139614+renovate[bot]@users.noreply.github.com&gt;
diff --git a/gradle.properties b/gradle.properties
@@ -1,4 +1,4 @@
 kotlin.code.style=official
-kotlin_version=2.0.20
+kotlin_version=2.0.21
 arrow_version=1.2.4
 okio_version=3.9.1
