Checkstyle: bump checkstyle to v10.23.0

Author: cagix

build.gradle

@@ -41,9 +41,9 @@ test {
 checkstyle {
     configFile = file('checkstyle.xml')
     // Default version vs. current version? The default version is quite old (9.3 from
-    // Jan 30, 2022), so let's go with the current version (10.17).
+    // Jan 30, 2022), so let's go with the current version (10.23.0).
     // However, this needs to be updated manually as Dependabot won't deal with this!
-    toolVersion = '10.19.0'
+    toolVersion = '10.23.0'
     ignoreFailures = false
     maxWarnings = 0
 }

checkstyle.xml

@@ -19,7 +19,7 @@
         <module name="JavadocTagContinuationIndentation"/>
         <module name="JavadocType"/>
         <module name="JavadocVariable">
-            <property name="scope" value="public"/>
+            <property name="accessModifiers" value="public"/>
         </module>
         <module name="MissingDeprecated"/>
         <module name="MissingJavadocMethod"/>