ci: set -euo pipefail

Author: kkebo

.github/workflows/ci.yml

@@ -5,6 +5,9 @@ on:
   pull_request:
     branches: ["main"]
 permissions: {}
+defaults:
+  run:
+    shell: bash -euo pipefail {0}
 jobs:
   build-linux:
     runs-on: ubuntu-24.04-arm