Update dependency org.yaml:snakeyaml to v2.1

Author: renovate[bot]

plugin-management-library/pom.xml

@@ -69,7 +69,7 @@
         <dependency>
             <groupId>org.yaml</groupId>
             <artifactId>snakeyaml</artifactId>
-            <version>2.0</version>
+            <version>2.1</version>
         </dependency>
         <dependency>
             <groupId>com.github.spotbugs</groupId>