chore: remove Windows support

- Removes coolify-testing-host.yml too, it published the testing host to Docker Hub for docker-compose.windows.yml alone, the development setup builds it locally

tests/Feature/PersistentImageStorageTest.php

@@ -16,11 +16,6 @@ it('persists images in stable and nightly production compose files', function (s
     'stable' => 'docker-compose.prod.yml',
 ]);
 
-it('persists images in the Windows compose file', function () {
-    expect(file_get_contents(base_path('docker-compose.windows.yml')))
-        ->toContain('./images:/var/www/html/storage/app/images');
-});
-
 it('creates the persistent image directory during installation and upgrades', function (string $script) {
     expect(file_get_contents(base_path($script)))
         ->toContain('/data/coolify/images');