Order "Check Website" workflow's steps according to the template

No functional difference, and neither is necessarily superior, but that is how it is in the template, and so it must be
here too.

Author: per1234

.github/workflows/check-mkdocs-task.yml

@@ -33,12 +33,6 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v2
 
-      - name: Install Task
-        uses: arduino/setup-task@v1
-        with:
-          repo-token: ${{ secrets.GITHUB_TOKEN }}
-          version: 3.x
-
       - name: Install Go
         uses: actions/setup-go@v2
         with:
@@ -54,6 +48,12 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install poetry
 
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
       - name: Build website
         # Ensure the documentation can build. These docs won't be published.
         run: task website:check