Apply suggestions from code review

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: timtebeek

src/main/java/org/openrewrite/java/migrate/guava/NoGuavaPredicatesInstanceOf.java

@@ -22,7 +22,6 @@
 import org.openrewrite.java.JavaIsoVisitor;
 import org.openrewrite.java.JavaTemplate;
 import org.openrewrite.java.MethodMatcher;
-import org.openrewrite.java.ShortenFullyQualifiedTypeReferences;
 import org.openrewrite.java.search.UsesMethod;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JavaType;

src/test/java/org/openrewrite/java/migrate/guava/NoGuavaPredicatesInstanceOfTest.java

@@ -18,7 +18,6 @@
 import org.junit.jupiter.api.Test;
 import org.openrewrite.DocumentExample;
 import org.openrewrite.InMemoryExecutionContext;
-import org.openrewrite.Issue;
 import org.openrewrite.java.JavaParser;
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;