ci: Add rules:changes:compare_to to the job rules

By default MR pipelines always compare against the
target branch, however branch pipelines compare
the difference of the last two commit.

This means that once we merge something, jobs that we
expected to run, might not depending on what the last
two commits touched.

Add rules:changes:compare_to: keyword so the behavior
is the same between branch and MR pipelines.

https://docs.gitlab.com/ee/ci/yaml/index.html#ruleschangescompare_to

Fixes: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/3780
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7507>

.gitlab-ci.yml

@@ -324,6 +324,7 @@ commitlint:
 .gtk-build-rules:
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - ".gitlab-ci.yml"
           - "meson.build"
@@ -360,9 +361,11 @@ commitlint:
   rules:
     - !reference [.upstream-branch-rules, rules]
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           *modules_changes
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "subprojects/gstreamer-vaapi/**/*"
 
@@ -482,9 +485,11 @@ build debian x86_64:
     - !reference [.gtk-build-rules, rules]
     - !reference [.upstream-branch-rules, rules]
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           *modules_changes
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "subprojects/win-*/*"
   script:
@@ -605,9 +610,11 @@ build macos:
     - !reference [.gtk-build-rules, rules]
     - !reference [.upstream-branch-rules, rules]
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           *modules_changes
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "subprojects/macos-*/*"
   parallel:
@@ -654,6 +661,7 @@ build macos:
     PYTHONFAULTHANDLER: "enabled"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           *modules_changes
   script:
@@ -692,9 +700,11 @@ check fedora:
     TEST_SUITE: "check.gst*"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           *modules_changes
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "subprojects/gstreamer-vaapi/**/*"
 
@@ -744,6 +754,7 @@ check video formats:
     - $CI_PROJECT_DIR/ci/scripts/check-video-formats.sh
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "${VIDEO_HEADER}"
           - "${WL_HEADER}"
@@ -837,6 +848,7 @@ fluster v4l2-stateless on visl:
       junit: build/fluster-results-*.xml
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - ".gitlab-ci.yml"
           - ".gitlab-image-tags.yml"
@@ -856,9 +868,11 @@ fluster v4l2-stateless on visl:
     EXTRA_VALIDATE_ARGS: "--valgrind"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           *modules_changes
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "subprojects/gstreamer-vaapi/**/*"
 
@@ -868,6 +882,7 @@ valgrind core:
     TEST_SUITE: "check.gstreamer\\..*"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "*"
           - "scripts/*"
@@ -881,6 +896,7 @@ valgrind base:
     TEST_SUITE: "check.gst-plugins-base\\..*"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "*"
           - "scripts/*"
@@ -897,6 +913,7 @@ valgrind good:
     TIMEOUT_FACTOR: "4"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "*"
           - "scripts/*"
@@ -912,6 +929,7 @@ valgrind ugly:
     TEST_SUITE: "check.gst-plugins-ugly\\..*"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "*"
           - "scripts/*"
@@ -928,6 +946,7 @@ valgrind bad:
     TEST_SUITE: "check.gst-plugins-bad\\..*"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "*"
           - "scripts/*"
@@ -944,6 +963,7 @@ valgrind ges:
     TEST_SUITE: "check.gst-editing-services\\..*"
   rules:
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - "*"
           - "scripts/*"
@@ -1015,6 +1035,7 @@ build documentation:
     - if: '$CI_PROJECT_NAMESPACE == "gstreamer" && $CI_COMMIT_BRANCH == $GST_UPSTREAM_BRANCH'
       when: never
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - ".gitlab-ci.yml"
           - ".gitlab-image-tags.yml"
@@ -1054,6 +1075,7 @@ cerbero trigger:
     - if: '$CI_PROJECT_NAMESPACE == "gstreamer" && $CI_COMMIT_BRANCH == $GST_UPSTREAM_BRANCH'
       when: never
     - changes:
+        compare_to: "$GST_UPSTREAM_BRANCH"
         paths:
           - ".gitlab-ci.yml"
           - "ci/gitlab/*.py"