remove unused import

Author: pway99

src/main/java/org/openrewrite/java/migrate/apache/commons/codec/ApacheBase64ToJavaBase64.java

@@ -22,7 +22,6 @@
 import org.openrewrite.java.MethodMatcher;
 import org.openrewrite.java.search.UsesType;
 import org.openrewrite.java.tree.J;
-import org.openrewrite.java.tree.JavaSourceFile;
 import org.openrewrite.java.tree.JavaType;
 
 import java.time.Duration;