fix(ci): resolve-versions needs shell: bash for 'set -o pipefail'

The default run shell is 'sh -e {0}' (dash on the act runner), which
rejects 'set -o pipefail' ('Illegal option -o pipefail') — failing the
resolve-versions job on line 2 and cascading every dependent job to
skipped (v1.1.6 run 401). The heavy build steps already declare
'shell: bash'; the resolve step did not. Added it.

.gitea/workflows/docker-publish.yml

@@ -129,6 +129,7 @@ jobs:
     steps:
       - name: Resolve pi version + companion refs
         id: resolve
+        shell: bash
         run: |
           set -euo pipefail
           AUTH_HEADER="Authorization: token ${GITEA_BUILD_TOKEN:-${GITHUB_TOKEN:-}}"