chore: promote creating 'caddy-build' to the release action (#4306)

The commit goreleaser/goreleaser@013bd69126 of GoReleaser is now checking the `go version` prior to executing any of the pre-hooks, which involves setting the current dir of the command to the `build.dir` of the build config. At the time of version check, the buil dir does not exist. It's created in the pre-hook. As a workaround, the build-dir is now created in the Github Action prior to executing goreleaser action.

.github/workflows/ci.yml

@@ -156,6 +156,10 @@ jobs:
     steps:
       - name: checkout
         uses: actions/checkout@v2
+
+      - name: Create 'caddy-build'
+        run: mkdir -p caddy-build
+      
       - uses: goreleaser/goreleaser-action@v2
         with:
           version: latest