chore(fix): remove unused dependency (#755)

Author: kolea2

pom.xml

@@ -161,11 +161,6 @@
         <artifactId>proto-google-cloud-datastore-admin-v1</artifactId>
         <version>2.5.2-SNAPSHOT</version><!-- {x-version-update:proto-google-cloud-datastore-admin-v1:current} -->
       </dependency>
-      <dependency>
-        <groupId>com.google.api.grpc</groupId>
-        <artifactId>grpc-google-cloud-datastore-v1</artifactId>
-        <version>2.5.2-SNAPSHOT</version><!-- {x-version-update:grpc-google-cloud-datastore-v1:current} -->
-      </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-datastore-admin-v1</artifactId>