Fix Safari artifact names

With the unified workflow, we don't actually need to specify the
wildcard, as this will just lead to errors like:

> Error: The artifact name is not valid:
> safari-technology-preview-results-*-6. Contains the following
> character: Asterisk *

e.g., in
https://github.com/web-platform-tests/wpt/actions/runs/11410328782/job/31752427266

.github/workflows/safari_stable.yml

@@ -31,6 +31,6 @@ jobs:
       github.event_name != 'workflow_run' || fromJSON(needs.check-workflow-run.outputs.updated-refs)[0] != null
     uses: ./.github/workflows/safari-wptrunner.yml
     with:
-      artifact-name: "safari-results-*"
+      artifact-name: "safari-results"
       safari-technology-preview: false
       safaridriver-diagnose: false

.github/workflows/safari_technology_preview.yml

@@ -31,6 +31,6 @@ jobs:
       github.event_name != 'workflow_run' || fromJSON(needs.check-workflow-run.outputs.updated-refs)[0] != null
     uses: ./.github/workflows/safari-wptrunner.yml
     with:
-      artifact-name: "safari-technology-preview-results-*"
+      artifact-name: "safari-technology-preview-results"
       safari-technology-preview: true
       safaridriver-diagnose: false