build(deps): bump gotify/server from 2.7.3 to 2.8.0 in /.ci

Bumps gotify/server from 2.7.3 to 2.8.0.

---
updated-dependencies:
- dependency-name: gotify/server
  dependency-version: 2.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.ci/docker-compose.yml

@@ -3,7 +3,7 @@ version: "3"
 services:
   gotify:
     container_name: ci_gotify
-    image: gotify/server:2.7.3
+    image: gotify/server:2.8.0
     ports:
       - "127.0.0.1:8080:80"
     environment: