update kibana constraint

Before version 8.3.0 a bug in the Fleet UI configuration conflict
resolution screen would prevent a successful update of this
package to the new version.

The constraint is updated on Kibana >= 8.3 where the related fix
landed[1] so we can guarantee a working upgrade path.

[1]: elastic/kibana#132068

packages/gcp/manifest.yml

@@ -15,7 +15,7 @@ categories:
   - google_cloud
   - cloud
 conditions:
-  kibana.version: ^7.17.0 || ^8.0.0
+  kibana.version: ^7.17.0 || ^8.3.0
 screenshots:
   - src: /img/filebeat-gcp-audit.png
     title: filebeat gcp audit