Add manual repository checkout step in GitHub Actions workflow for linux_amd64 build to ensure proper initialization and status verification.

.github/workflows/build-linux-amd64.yml

@@ -16,10 +16,32 @@ jobs:
       EXTENSION_NAME: ui
       DUCKDB_PLATFORM: linux_amd64
     steps:
+      - name: Checkout repository (manual)
+        env:
+          TOKEN: ${{ secrets.GITEA_TOKEN }}
+        run: |
+          set -euo pipefail
+          if [ -d .git ]; then
+            echo "Repository already present"
+          else
+            server="${GITHUB_SERVER_URL:-${{ github.server_url }}}"
+            repo_full="${GITHUB_REPOSITORY:-${{ github.repository }}}"
+            sha="${GITHUB_SHA:-${{ github.sha }}}"
+            host="$(echo "$server" | sed -E 's#^https?://([^/]+).*#\1#')"
+            if [ -n "${TOKEN:-}" ]; then
+              umask 077
+              printf "machine %s\n  login token\n  password %s\n" "$host" "$TOKEN" > "$HOME/.netrc"
+            fi
+            git init .
+            git config --global --add safe.directory "$(pwd)"
+            git remote add origin "$server/$repo_full.git"
+            git -c http.https://$host/.extraheader="" fetch --depth=1 origin "$sha"
+            git checkout -q FETCH_HEAD
+          fi
+
       - name: Show workspace status
         run: |
           set -e
-          test -d .git || { echo "Repository not checked out in workspace" >&2; exit 1; }
           git --no-pager status | cat
       - name: Install build dependencies
         run: |