fix(ci): use rhysd/actionlint action instead of npx

actionlint is a Go binary; there is no npm package by that name.
npx --yes actionlint@latest fails with 'could not determine executable
to run'. Use the official rhysd/actionlint action instead.

Author: AlbinoGeek

.github/workflows/ci.yml

@@ -19,9 +19,6 @@ jobs:
       - uses: actions/checkout@v6
 
       - name: Validate workflow files
-        run: |
-          if ls .github/workflows/*.yml 2>/dev/null; then
-            npx --yes actionlint@latest .github/workflows/*.yml
-          else
-            echo "No workflow files to lint"
-          fi
+        uses: rhysd/actionlint@v1.7.12
+        with:
+          files: .github/workflows/*.yml