Remove unused checkstyle linter. (#731) (#733)

(cherry picked from commit 11b829d)

Signed-off-by: Finn Carroll <carrofin@amazon.com>
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: opensearch-trigger-bot[bot]

build.gradle

@@ -44,7 +44,6 @@ buildscript {
 plugins {
     id "de.undercouch.download" version "5.3.0"
     id 'com.netflix.nebula.ospackage' version "11.10.0"
-    id 'checkstyle'
     id "com.diffplug.spotless" version "6.25.0"
 }
 
@@ -63,12 +62,6 @@ apply plugin: 'opensearch.rest-test'
 apply plugin: 'opensearch.pluginzip'
 apply from: 'gradle/formatting.gradle'
 
-
-checkstyle {
-    toolVersion = '10.12.1'
-    configFile file("checkstyle/checkstyle.xml")
-}
-
 def usingRemoteCluster = System.properties.containsKey('tests.rest.cluster') || System.properties.containsKey('tests.cluster')
 def usingMultiNode = project.properties.containsKey('numNodes')
 // Only apply jacoco test coverage if we are running a local single node cluster
@@ -153,7 +146,6 @@ dependencies {
     configurations.all {
         resolutionStrategy {
             force "com.google.guava:guava:32.1.3-jre"
-            force "com.puppycrawl.tools:checkstyle:${project.checkstyle.toolVersion}"
         }
     }
 }