fix: change deprecated import for NonNull

Author: Zorin95670

cmtp/src/main/java/io/github/linagora/linid/im/cmtp/ContextMapperTaskPlugin.java

@@ -34,8 +34,8 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import org.jspecify.annotations.NonNull;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.lang.NonNull;
 import org.springframework.stereotype.Component;
 import tools.jackson.core.type.TypeReference;