Adapt to bazel 9.1.0 update

Change-Id: Ide487dc00889e897eb8a0fd0bb7aa83b90bc2a51
diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewers/PostReviewers.java b/src/main/java/com/googlesource/gerrit/plugins/reviewers/PostReviewers.java
index c65e406..ebba7c4 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewers/PostReviewers.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewers/PostReviewers.java
@@ -176,13 +176,13 @@
     try {
       UnresolvableAccountException accountException;
       try {
-        accountResolver.resolve(reviewer).asUnique();
+        var unused = accountResolver.resolve(reviewer).asUnique();
         return;
       } catch (UnresolvableAccountException e) {
         accountException = e;
       }
       try {
-        groupResolver.get().parse(reviewer);
+        var unused = groupResolver.get().parse(reviewer);
       } catch (UnprocessableEntityException e) {
         throw new ResourceNotFoundException(
             "Account or group '" + reviewer + "' not found\n" + accountException.getMessage());
diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewers/config/ReviewersQueryValidator.java b/src/main/java/com/googlesource/gerrit/plugins/reviewers/config/ReviewersQueryValidator.java
index 4793a57..018ab24 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewers/config/ReviewersQueryValidator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewers/config/ReviewersQueryValidator.java
@@ -31,6 +31,6 @@
   }
 
   void validateQuery(String query) throws QueryParseException {
-    queryBuilder.get().parse(query);
+    var unused = queryBuilder.get().parse(query);
   }
 }