chore: regenerate README (#271)

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Author: yoshi-automation

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-trace</artifactId>
-  <version>1.1.0</version>
+  <version>1.2.1</version>
 </dependency>
 
 ```

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-trace.git",
-        "sha": "f1dd2061682b2e3c797d73e7a3ad4d28e9060d64"
+        "sha": "3ab96afdcc43b12c3b750f25efd2913ef621cc74"
       }
     },
     {