chore: regenerate README (#518)

Author: yoshi-automation

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

@@ -4,14 +4,14 @@
  "git": {
  "name": ".",
  "remote": "https://github.com/googleapis/java-spanner.git",
- "sha": "44882238f73e3659306e6c63aa652e7a0bc6e43f"
+ "sha": "273f40c0b8b86aea1e1c9f54ca13723d4ce97298"
  }
  },
  {
  "git": {
  "name": "synthtool",
  "remote": "https://github.com/googleapis/synthtool.git",
- "sha": "b6164c26a111f7f587099d31253abb96b5737bb2"
+ "sha": "d5d03413e1879108b5ade8839ce38de01be652da"
  }
  }
  ]

README.md

@@ -17,7 +17,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
  <dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>libraries-bom</artifactId>
- <version>12.0.0</version>
+ <version>12.1.0</version>
  <type>pom</type>
  <scope>import</scope>
  </dependency>
@@ -43,8 +43,6 @@ If you are using Maven without BOM, add this to your dependencies:
 
 ```
 
-[//]: # ({x-version-update-start:google-cloud-spanner:released})
-
 If you are using Gradle, add this to your dependencies
 ```Groovy
 compile 'com.google.cloud:google-cloud-spanner:2.0.2'
@@ -53,7 +51,6 @@ If you are using SBT, add this to your dependencies
 ```Scala
 libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "2.0.2"
 ```
-[//]: # ({x-version-update-end})
 
 ## Authentication