CI: clone the main branch in the dev-track job

The job still checked out `dev`, which no longer exists.

.forgejo/workflows/dev-release.yml

@@ -16,7 +16,7 @@ jobs:
         run: |
           set -euo pipefail
           rm -rf src && mkdir src
-          git clone --branch dev --depth 1 \
+          git clone --branch main --depth 1 \
             "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" src
 
       - name: build