CI: Fix openQA for not published TW snapshot

The openQA CI tests trigger only looked up the
latest Tumbleweed snapshot and then selecting the
"published" one which fails if the latest snapshot
was actually not published, as happened on
20240718.

Instead of filtering the builds to 1 and then
assuming we can select "published" from that list
this commit changes the lookup to read the default
number of builds, which is by default 10, and then
selects the latest published.

Related progress issue: https://progress.opensuse.org/issues/164210

.github/workflows/openqa.yml

@@ -28,8 +28,9 @@ jobs:
         run: >-
           echo build=$(openqa-cli api
           --host ${OPENQA_HOST:-https://openqa.opensuse.org}
-          job_groups/${OPENQA_BUILD_LOOKUP_GROUP_ID:-1}/build_results limit_builds=1 only_tagged=1
-          | jq -r '[ .build_results[] | select(.tag.description=="published") | .build ][]'
+          job_groups/${OPENQA_BUILD_LOOKUP_GROUP_ID:-1}/build_results only_tagged=1
+          | jq -r '[ .build_results[] | select(.tag.description=="published") | .build ][0]'
+
           ) >> "$GITHUB_OUTPUT"
       - name: Trigger and monitor a basic openQA test on o3
         run: >-