abandon idk change detection for now

the "changes" rule appears not to be good at detecting changes
in some cases. specifically, it appears that you have to be in
an "only:" clause, not a "rules" clause, to trigger the
merge-specific behavior which checks the entire merge branch
instead of the top commit, but that means that if your last
commit doesn't touch IDK, we don't run IDK tests, and I haven't
been able to fix this yet.

So for now, revert the IDK-specific change detection behavior,
which slows CI down but gets us test coverage.

.gitlab/.gitlab-ci.yml

@@ -275,9 +275,6 @@ run go tests idk race:
   retry: 1
   rules:
     - if: '$CI_COMMIT_TAG == null && ($CI_PIPELINE_SOURCE == "push" || $CI_PIPELINE_SOURCE == "schedule" || $CI_PIPELINE_SOURCE == "web")'
-      changes:
-        - idk
-        - client
   script:
     - echo "Running test-all-race"
     - cd ./idk/
@@ -309,9 +306,6 @@ run go tests idk shard transactional:
   retry: 1
   rules:
     - if: '$CI_COMMIT_TAG == null && ($CI_PIPELINE_SOURCE == "push" || $CI_PIPELINE_SOURCE == "schedule" || $CI_PIPELINE_SOURCE == "web")'
-      changes:
-        - idk
-        - client
   script:
     - echo "Running shard transactional tests"
     - cd ./idk/
@@ -352,9 +346,6 @@ run go tests idk 533:
     - make shutdown
   rules:
     - if: '$CI_COMMIT_TAG == null && ($CI_PIPELINE_SOURCE == "push" || $CI_PIPELINE_SOURCE == "schedule" || $CI_PIPELINE_SOURCE == "web")'
-      changes:
-        - idk
-        - client
   tags:
     - shell
     - aws
@@ -384,9 +375,6 @@ run go tests idk sasl:
     - make shutdown
   rules:
     - if: '$CI_COMMIT_TAG == null && ($CI_PIPELINE_SOURCE == "push" || $CI_PIPELINE_SOURCE == "schedule" || $CI_PIPELINE_SOURCE == "web")'
-      changes:
-        - idk
-        - client
   tags:
     - shell
     - aws