ci/build: fix ppc64le and s390x jobs rules

I think these were written with the idea of making it "(build rules) &&
(any relevant driver), but instead the driver rules are bypassing the
build rules because
1) it's not an AND, it's an OR; any line that matches applies, and
2) the driver rules are `when: on_success` when these need to be `when:
   manual` like the rest of the build jobs.

Let's stop trying to be special and simply behave like all the other
build jobs.

We can always try making complex rules later, but once we're on a base
that works.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30871>

.gitlab-ci/build/gitlab-ci.yml

@@ -697,7 +697,6 @@ debian-s390x:
   extends:
     - debian-ppc64el
     - .use-debian/s390x_build
-    - .s390x-rules
   tags:
     - kvm
   variables:
@@ -712,7 +711,6 @@ debian-ppc64el:
   extends:
     - .meson-cross
     - .use-debian/ppc64el_build
-    - .ppc64el-rules
   variables:
     BUILDTYPE: debug
     CROSS: ppc64el

.gitlab-ci/test-source-dep.yml

@@ -208,28 +208,6 @@
         *vulkan_file_list
       when: manual
 
-# Rules for unusual architectures that only build a subset of drivers
-.ppc64el-rules:
-  rules:
-    - !reference [.never-post-merge-rules, rules]
-    - !reference [.no_scheduled_pipelines-rules, rules]
-    - !reference [.zink-common-rules, rules]
-    - !reference [.softpipe-rules, rules]
-    - !reference [.llvmpipe-rules, rules]
-    - !reference [.lavapipe-rules, rules]
-    - !reference [.radv-rules, rules]
-    - !reference [.radeonsi-rules, rules]
-    - !reference [.virgl-rules, rules]
-    - !reference [.nouveau-rules, rules]
-
-.s390x-rules:
-  rules:
-    - !reference [.never-post-merge-rules, rules]
-    - !reference [.no_scheduled_pipelines-rules, rules]
-    - !reference [.zink-common-rules, rules]
-    - !reference [.llvmpipe-rules, rules]
-    - !reference [.lavapipe-rules, rules]
-
 # Rules for linters
 .lint-rustfmt-rules:
   rules: