Add extra flags to check integrity and only upload the recipe

Author: bthomee

.github/workflows/export.yml

@@ -41,4 +41,7 @@ jobs:
           conan export snappy/all --version=1.1.10
           conan export soci/all --version=4.0.3
       - name: Upload the recipes
-        run: conan upload '*' --confirm --remote ${{ env.CONAN_REMOTE_NAME }}
+        run: |
+          conan upload '*' --confirm --check --only-recipe \
+          --remote ${{ env.CONAN_REMOTE_NAME }} \
+          ${{ github.ref_type == 'branch' && github.ref_name == github.event.repository.default_branch && '' || '--dryrun'}}