Use the released pom parent

Author: suztomo

java-vertexai/google-cloud-vertexai-bom/pom.xml

@@ -9,7 +9,7 @@
   <parent>
     <groupId>com.google.cloud</groupId>
     <artifactId>google-cloud-pom-parent</artifactId>
-    <version>1.54.1</version><!-- {x-version-update:google-cloud-java:current} -->
+    <version>1.54.0</version><!-- {x-version-update:google-cloud-java:current} -->
     <relativePath>../../google-cloud-pom-parent/pom.xml</relativePath>
   </parent>