Remove parentheses from single unnamed lambda parameters

src/main/java/org/openrewrite/java/migrate/lang/ReplaceUnusedVariablesWithUnderscore.java

@@ -70,22 +70,31 @@ public J.Try.Catch visitCatch(J.Try.Catch _catch, ExecutionContext ctx) {
             @Override
             public J.Lambda visitLambda(J.Lambda lambda, ExecutionContext ctx) {
                 J.Lambda l = super.visitLambda(lambda, ctx);
+                boolean willRename = false;
                 for (J param : l.getParameters().getParameters()) {
                     if (param instanceof J.VariableDeclarations) {
                         for (J.VariableDeclarations.NamedVariable namedVariable : ((J.VariableDeclarations) param).getVariables()) {
-                            renameVariableIfUnusedInContext(namedVariable, l.getBody());
+                            if (renameVariableIfUnusedInContext(namedVariable, l.getBody())) {
+                                willRename = true;
+                            }
                         }
                     }
                 }
+                if (willRename && l.getParameters().isParenthesized() &&
+                        l.getParameters().getParameters().size() == 1) {
+                    l = l.withParameters(l.getParameters().withParenthesized(false));
+                }
                 return l;
             }
 
-            private void renameVariableIfUnusedInContext(J.VariableDeclarations.NamedVariable variable, J context) {
+            private boolean renameVariableIfUnusedInContext(J.VariableDeclarations.NamedVariable variable, J context) {
                 if (!UNDERSCORE.equals(variable.getName().getSimpleName()) &&
                         VariableReferences.findRhsReferences(context, variable.getName()).isEmpty() &&
                         !usedInModifyingUnary(variable.getName(), context)) {
                     doAfterVisit(new RenameVariable<>(variable, UNDERSCORE));
+                    return true;
                 }
+                return false;
             }
 
             private boolean usedInModifyingUnary(J.Identifier identifier, J context) {

src/test/java/org/openrewrite/java/migrate/lang/ReplaceUnusedVariablesWithUnderscoreTest.java

@@ -174,6 +174,37 @@ void example() {
         );
     }
 
+    @Test
+    void replaceUnusedParenthesizedLambdaParameter() {
+        rewriteRun(
+          //language=java
+          java(
+            """
+              import java.util.stream.Stream;
+              import java.util.stream.Collectors;
+
+              class Test {
+                  void example() {
+                      Stream.of("a", "b", "c")
+                          .collect(Collectors.toMap(String::toUpperCase, (item) -> "NODATA"));
+                  }
+              }
+              """,
+            """
+              import java.util.stream.Stream;
+              import java.util.stream.Collectors;
+
+              class Test {
+                  void example() {
+                      Stream.of("a", "b", "c")
+                          .collect(Collectors.toMap(String::toUpperCase, _ -> "NODATA"));
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void doNotReplaceUsedLambdaParameter() {
         rewriteRun(