gitlabci: Extend the expiration period of the flatpak bundle

It's often the case that an MR will be opened and call for testing or an artifact will be linked in an issue.
But by the time people review the changes or try to test it them, the provided bundle will be already gone.

In the early days of the gitlab migration the expiration was commonly set to a small interval to ease the transition and not eat up the resources of runners. This should no longer be required going forward and the expiration date can be more flexible.

.gitlab-ci.yml

@@ -39,7 +39,7 @@ flatpak:
             - ${BUNDLE}
             - _build/meson-logs/meson-log.txt
             - _build/meson-logs/testlog.txt
-        expire_in: 2 days
+        expire_in: 30 days
     cache:
         paths:
             - .flatpak-builder/cache
@@ -53,7 +53,7 @@ review:
     artifacts:
         paths:
             - ${BUNDLE}
-        expire_in: 2 days
+        expire_in: 30 days
     environment:
         name: review/$CI_COMMIT_REF_NAME
         url: https://gitlab.gnome.org/$CI_PROJECT_PATH/-/jobs/$CI_JOB_ID/artifacts/raw/${BUNDLE}