fix: use Ruby 3.3.11 in markdown checks workflow

3.3.11 was released on 2026-03-26. CI will pass once PR #2133 bumps
the pinned ruby/setup-ruby SHA.

Author: YousefHadder

.github/workflows/ci-markdown-checks.yml

@@ -93,7 +93,7 @@ jobs:
       - name: Install Ruby
         uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
         with:
-          ruby-version: "3.3.0"
+          ruby-version: "3.3.11"
 
       - name: Install Tools
         run: npm ci --ignore-scripts && bundle install
@@ -149,7 +149,7 @@ jobs:
       - name: Install Ruby
         uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
         with:
-          ruby-version: "3.3.0"
+          ruby-version: "3.3.11"
 
       - name: Install Tools
         run: npm ci --ignore-scripts && bundle install