chore: release 0.120.8 (#313)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Author: release-please[bot]

errorreporting/snapshot/pom.xml

@@ -28,7 +28,7 @@
     <dependency>
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-errorreporting</artifactId>
-      <version>0.120.8-beta-SNAPSHOT</version>
+      <version>0.120.8-beta</version>
     </dependency>
     <!-- {x-version-update-end} -->