Upgrade to modernizer-maven-plugin 3.1.0

This improves local variable suppressions.

pom.xml

@@ -333,7 +333,7 @@
       <plugin>
         <groupId>org.gaul</groupId>
         <artifactId>modernizer-maven-plugin</artifactId>
-        <version>3.0.0</version>
+        <version>${modernizer.version}</version>
         <executions>
           <execution>
             <id>modernizer</id>
@@ -345,9 +345,6 @@
         </executions>
         <configuration>
           <javaVersion>${java.version}</javaVersion>
-          <exclusions>
-            <exclusion>com/google/common/base/Supplier</exclusion>
-          </exclusions>
         </configuration>
       </plugin>
       <plugin>
@@ -369,6 +366,7 @@
     <java.version>11</java.version>
     <jclouds.version>2.6.0</jclouds.version>
     <jetty.version>11.0.24</jetty.version>
+    <modernizer.version>3.1.0</modernizer.version>
     <slf4j.version>2.0.16</slf4j.version>
     <shade.prefix>${project.groupId}.shaded</shade.prefix>
     <surefire.version>3.2.5</surefire.version>
@@ -509,6 +507,11 @@
       <artifactId>jetty-servlet</artifactId>
       <version>${jetty.version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.gaul</groupId>
+      <artifactId>modernizer-maven-annotations</artifactId>
+      <version>${modernizer.version}</version>
+    </dependency>
     <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-api</artifactId>

src/main/java/org/gaul/s3proxy/Main.java

@@ -46,6 +46,7 @@ import com.google.common.collect.ImmutableMap;
 import com.google.common.io.MoreFiles;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 
+import org.gaul.modernizer_maven_annotations.SuppressModernizer;
 import org.jclouds.Constants;
 import org.jclouds.ContextBuilder;
 import org.jclouds.JcloudsVersion;
@@ -392,7 +393,8 @@ public final class Main {
         }
 
         if ((identity.isEmpty() || credential.isEmpty()) && provider.equals("aws-s3")) {
-            var credentialsSupplier = new Supplier<Credentials>() {
+            @SuppressModernizer
+            Supplier<Credentials> credentialsSupplier = new Supplier<Credentials>() {
                 @Override
                 public Credentials get() {
                     AWSCredentialsProvider authChain = DefaultAWSCredentialsProviderChain.getInstance();