Use new download server

windows.php.net is in the process of being replaced by
downloads.php.net, so we switch right away.

.github/workflows/build-windows.yml

@@ -28,7 +28,7 @@ jobs:
           deps: zlib
           cache: true
       - name: Fetch libmemcached
-        run: curl -OLs https://windows.php.net/downloads/pecl/deps/libmemcached-1.1.1-${{steps.setup-php.outputs.vs}}-${{matrix.arch}}.zip && 7z x libmemcached-1.1.1-${{steps.setup-php.outputs.vs}}-${{matrix.arch}}.zip -o..\deps
+        run: curl -OLs https://downloads.php.net/~windows/pecl/deps/libmemcached-1.1.1-${{steps.setup-php.outputs.vs}}-${{matrix.arch}}.zip && 7z x libmemcached-1.1.1-${{steps.setup-php.outputs.vs}}-${{matrix.arch}}.zip -o..\deps
       - name: Enable Developer Command Prompt
         uses: ilammy/msvc-dev-cmd@v1
         with: