Remove a useless `allow_failure: no` and use `true` instead of `yes`

Signed-off-by: Rémy Coutable <remy@rymai.me>

.gitlab-ci.yml

@@ -256,7 +256,7 @@ flaky-examples-check:
     USE_BUNDLE_INSTALL: "false"
     NEW_FLAKY_SPECS_REPORT: rspec_flaky/report-new.json
   stage: post-test
-  allow_failure: yes
+  allow_failure: true
   retry: 0
   only:
     - branches
@@ -416,7 +416,6 @@ ee_compat_check:
     - /^[\d-]+-stable(-ee)?/
     - branches@gitlab-org/gitlab-ee
     - branches@gitlab/gitlab-ee
-  allow_failure: no
   retry: 0
   artifacts:
     name: "${CI_JOB_NAME}_${CI_COMIT_REF_NAME}_${CI_COMMIT_SHA}"