deps: update dependency com.google.auth:google-auth-library-bom to v0.18.0 (#56)

Author: renovate-bot

pom.xml

@@ -156,7 +156,7 @@
     <google.api-common.version>1.8.1</google.api-common.version>
     <google.common-protos.version>1.17.0</google.common-protos.version>
     <google.iam.version>0.13.0</google.iam.version>
-    <google.auth.version>0.17.2</google.auth.version>
+    <google.auth.version>0.18.0</google.auth.version>
     <google.api.version>1.30.4</google.api.version>
     <google.http.version>1.32.1</google.http.version>
     <grpc.version>1.24.0</grpc.version>