chore: bump self version (#597)

autosynth cannot find the source of changes triggered by earlier changes in this
        repository, or by version upgrades to tools such as linters.

.github/readme/synth.metadata/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquerystorage.git",
-        "sha": "abe21f02f811391259ebe921fff194a3a0394032"
+        "sha": "65b3a29f3e5c8567b2878ea053b2b351819bec19"
       }
     },
     {

README.md

@@ -38,7 +38,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigquerystorage</artifactId>
-  <version>1.5.4</version>
+  <version>1.5.5</version>
 </dependency>
 
 ```