Add doc/administration/raketasks/maintenance.md to backstage patterns

The spec/features/dashboard/help_spec.rb test file is relying on the
content of this documentation file.
Signed-off-by: Rémy Coutable <remy@rymai.me>

.gitlab/ci/rules.gitlab-ci.yml

@@ -78,6 +78,7 @@
   - "{,ee/}rubocop/**/*"
   - "{,ee/}spec/**/*"
   - "doc/README.md"  # Some RSpec test rely on this file
+  - "doc/administration/raketasks/maintenance.md"  # Some RSpec test rely on this file
 
 .code-patterns: &code-patterns
   - "{package.json,yarn.lock}"
@@ -121,6 +122,7 @@
   - "{,ee/}rubocop/**/*"
   - "{,ee/}spec/**/*"
   - "doc/README.md"  # Some RSpec test rely on this file
+  - "doc/administration/raketasks/maintenance.md"  # Some RSpec test rely on this file
 
 .code-qa-patterns: &code-qa-patterns
   - "{package.json,yarn.lock}"
@@ -163,6 +165,7 @@
   - "{,ee/}rubocop/**/*"
   - "{,ee/}spec/**/*"
   - "doc/README.md"  # Some RSpec test rely on this file
+  - "doc/administration/raketasks/maintenance.md"  # Some RSpec test rely on this file
   # QA changes
   - ".dockerignore"
   - "qa/**/*"