Adapt to bazel 9.1.0 update

Change-Id: I88e0cbaa9b0bb406f910345111e0732454955408

src/test/java/com/gerritforge/gerrit/globalrefdb/validation/ValidationModuleTest.java

diff --git a/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/ValidationModuleTest.java b/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/ValidationModuleTest.java
index 2330df2..7273dce 100644
--- a/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/ValidationModuleTest.java
+++ b/src/test/java/com/gerritforge/gerrit/globalrefdb/validation/ValidationModuleTest.java
@@ -35,17 +35,17 @@
 
   @Test
   public void shouldSetupValidationWithEmptyIgnoredRefs() throws Exception {
-    installPlugin("test-plugin", ValidationModuleWithEmptyIgnoredRefs.class);
+    var unused = installPlugin("test-plugin", ValidationModuleWithEmptyIgnoredRefs.class);
   }
 
   @Test
   public void shouldSetupValidationWithNonEmptyIgnoredRefs() throws Exception {
-    installPlugin("test-plugin", ValidationModuleWithNonEmptyIgnoredRefs.class);
+    var unused = installPlugin("test-plugin", ValidationModuleWithNonEmptyIgnoredRefs.class);
   }
 
   @Test
   public void shouldSetupValidationWithoutIgnoredRefs() throws Exception {
-    installPlugin("test-plugin", ValidationModuleWithoutIgnoredRefs.class);
+    var unused = installPlugin("test-plugin", ValidationModuleWithoutIgnoredRefs.class);
   }
 
   public static class ValidationModuleWithNonEmptyIgnoredRefs extends ValidationModule {