Revert "Remove version number from opentelemetry exporter-trace dependency"

This reverts commit 66856a8.

Author: manu2

google-cloud-spanner/pom.xml

@@ -458,6 +458,7 @@
     <dependency>
       <groupId>com.google.cloud.opentelemetry</groupId>
       <artifactId>exporter-trace</artifactId>
+      <version>0.33.0</version>
       <scope>test</scope>
     </dependency>
     <dependency>