fix(ci): Mark notify jobs as allowed to fail (#1062)

Author: Ishirui

.gitlab/notify.yml

@@ -10,6 +10,7 @@ notify-images-available:
       when: never
     - when: on_success
   dependencies: []
+  allow_failure: true
   script: |
     COMMIT_URL="$CI_PROJECT_URL/commit/$CI_COMMIT_SHA"
     BRANCH_URL="$CI_PROJECT_URL/tree/$CI_COMMIT_BRANCH"
@@ -29,6 +30,7 @@ notify-images-failure:
       when: never
     - when: on_failure
   dependencies: []
+  allow_failure: true
   script: |
     COMMIT_URL="$CI_PROJECT_URL/commit/$CI_COMMIT_SHA"
     BRANCH_URL="$CI_PROJECT_URL/tree/$CI_COMMIT_BRANCH"
@@ -43,6 +45,7 @@ notify-on-failure:
     - if: $CI_COMMIT_BRANCH == "master" || $CI_COMMIT_BRANCH == "main"
       when: on_failure
   dependencies: []
+  allow_failure: true
   script: |
     COMMIT_URL="$CI_PROJECT_URL/commit/$CI_COMMIT_SHA"
     AUTHOR=$(git show -s --format="%an" HEAD)