GH Actions: version update for various predefined actions

A number of predefined actions have had major release, which warrant an update the workflow(s).

These updates don't actually contain any changed functionality, they are mostly just a change of the Node version used by the action itself (from Node 14 to Node 16).

Refs:
* https://github.com/actions/download-artifact/releases
* https://github.com/actions/upload-artifact/releases

.github/workflows/docs.yml

@@ -40,7 +40,7 @@ jobs:
           php -m | Out-File -FilePath "$env:file" -Append
           Write-Output "```````n" | Out-File -FilePath "$env:file" -Append
       - name: Upload artifacts
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
         with:
           name: lists
           path: php${{ matrix.php-versions }}-${{ matrix.operating-system }}.md
@@ -54,7 +54,7 @@ jobs:
         with:
           repository: ${{ github.repository }}.wiki
       - name: Download artifacts
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v3
         with:
           path: ${{ github.workspace }}
       - name: Configure Git