Revert "OBS: build Fedora/Debian/Ubuntu x86_64 packages on PRs"

This does not work yet, as we configure multiple git sources,
and the workflow service gets confused. We need to update one
(the actual code repo) and leave the recipe repos intact, but
this is not supported right now.

This reverts commit 01f05f0087.

.obs/workflows.yml

@@ -11,36 +11,3 @@ rebuild:
     branches:
       only:
         - main
-pull_request:
-  steps:
-    - branch_package:
-        source_project: home:bluca:systemd
-        source_package: systemd
-        target_project: home:bluca:systemd:ci
-    - branch_package:
-        source_project: home:bluca:systemd
-        source_package: systemd-fedora
-        target_project: home:bluca:systemd:ci
-    - configure_repositories:
-        project: home:bluca:systemd:ci
-        repositories:
-          - name: Debian_Testing
-            paths:
-              - target_project: home:bluca:systemd
-                target_repository: Debian_Testing
-            architectures:
-              - x86_64
-          - name: Ubuntu_24.04
-            paths:
-              - target_project: home:bluca:systemd
-                target_repository: Ubuntu_24.04
-            architectures:
-              - x86_64
-          - name: Fedora_41
-            paths:
-              - target_project: home:bluca:systemd
-                target_repository: Fedora_41
-            architectures:
-              - x86_64
-  filters:
-    event: pull_request