test: make it easier to comment out tests

When the build stage is commented out, the /srv/forgejo-binaries
directory will not exist. Change the script to work in both cases.

.forgejo/prepare-end-to-end/action.yml

@@ -21,8 +21,9 @@ runs:
           path: /srv/forgejo-binaries
       - name: chown/chmod /srv/forgejo-binaries
         run: |
-          chmod +x /srv/forgejo-binaries/*
+          mkdir -p /srv/forgejo-binaries
           chown -R forgejo /srv/forgejo-binaries
+          chmod -R +x /srv/forgejo-binaries
       - run: |
           script=$(pwd)/end-to-end.sh
           $script run dependencies