fix: declare test dependency

google-cloud-spanner/pom.xml

@@ -417,6 +417,12 @@
       <version>${opentelemetry.version}</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>io.opentelemetry</groupId>
+      <artifactId>opentelemetry-sdk-common</artifactId>
+      <version>${opentelemetry.version}</version>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>io.opentelemetry</groupId>
       <artifactId>opentelemetry-sdk-metrics</artifactId>