Bazel: Trigger PolyGerrit verification for .bzlmod changes

Include `.bzlmod` files in the Bazel-related change detection so that
PolyGerrit validation is triggered when module definitions are modified.

This ensures UI verification runs for Bazel module changes, aligning
behavior with existing handling of WORKSPACE, BUILD, and .bzl files.

Change-Id: I7ce01a51319aeb946892930fd1a5ded05a039ed3

vars/gerritPipeline.groovy

diff --git a/vars/gerritPipeline.groovy b/vars/gerritPipeline.groovy
index e50045a..da9549a 100644
--- a/vars/gerritPipeline.groovy
+++ b/vars/gerritPipeline.groovy
@@ -141,7 +141,7 @@
     def polygerritFiles = changedFiles.findAll { it.startsWith("polygerrit-ui") ||
         it.startsWith("lib/js") }
     def bazelFiles = changedFiles.findAll { it == "WORKSPACE" || it.endsWith("BUILD") ||
-        it.endsWith(".bzl") || it == ".bazelversion" }
+        it.endsWith(".bzl") || it.endsWith(".bzlmod") || it == ".bazelversion" }
     if(isMerge) {
         println "Merge commit detected, adding 'polygerrit' validation..."
         Builds.modes += "polygerrit"