ci: increase timeout for file-plug-in-tests

The file-plug-in-tests sometimes fail due to timeout on slower runners.
Let's see if increasing it from the default 20 to 30 minutes helps.

Author: Wormnest

.gitlab-ci.yml

@@ -595,6 +595,7 @@ file-plug-in-tests:
     reports:
       junit: "_log/import-tests.xml"
     expire_in: 2 days
+  timeout: 30m
 
 meson-health:
   extends: .default