fix: re-adds test-jar to bom definition (#1596)

* fix: re-adds test-jar to bom definition

The test jar was wrongly removed during the owlbot migration.

* 🦉 Updates from OwlBot

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* chore: add google-cloud-spanner-bom to the ignore list for owlbot

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Neenu1995 <neenushaji@google.com>

.repo-metadata.json

@@ -14,6 +14,7 @@
   "api_id": "spanner.googleapis.com",
   "transport": "grpc",
   "requires_billing": true,
-  "codeowner_team": "@googleapis/api-spanner-java"
+  "codeowner_team": "@googleapis/api-spanner-java",
+  "excluded_poms": "google-cloud-spanner-bom"
 }
 

google-cloud-spanner-bom/pom.xml

@@ -55,6 +55,12 @@
         <artifactId>google-cloud-spanner</artifactId>
         <version>6.17.3-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
       </dependency>
+      <dependency>
+        <groupId>com.google.cloud</groupId>
+        <artifactId>google-cloud-spanner</artifactId>
+        <type>test-jar</type>
+        <version>6.17.3-SNAPSHOT</version><!-- {x-version-update:google-cloud-spanner:current} -->
+      </dependency>
       <dependency>
         <groupId>com.google.api.grpc</groupId>
         <artifactId>grpc-google-cloud-spanner-v1</artifactId>