[CONFIG] [Github Actions] markdownlint run simplified.

Author: Gonzalo Diaz

.github/workflows/markdown-lint.yml

@@ -10,13 +10,9 @@ on: # yamllint disable-line rule:truthy
 jobs:
   build:
     runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        os: ["ubuntu-latest"]
-        node-version: [20.x]
-        # See supported Node.js release
-        # schedule at https://nodejs.org/en/about/releases/
+    node-version: [20.x]
+    # See supported Node.js release
+    # schedule at https://nodejs.org/en/about/releases/
 
     steps:
       - name: Checkout repository