chore: Remove unused variable.

.forgejo/workflows/build.yml

@@ -218,14 +218,13 @@ jobs:
             });
 
             const {owner, repo} = context.repo;
-            const run_id = ${{ forgejo.run_id }};
-            const pull_head_sha = '${{ forgejo.event.workflow_run.head_sha }}';
+            const run_id = ${{ forgejo.run_number }};
 
             const issue_number = ${{ forgejo.event.pull_request.number }};
             core.info(`Using pull request ${issue_number}`);
 
             const {data: {artifacts}} = await forgejo.rest.actions.listWorkflowRunArtifacts({owner, repo, run_id});
-            if (!artifacts.length) {
+            if (artifacts == undefined || !artifacts.length) {
               return core.error(`No artifacts found`);
             }
             let body = `Download the artifacts for this pull request:\n`;