build(updating): Add WinRT coroutine support and refactor async methods (#45522)

## Summary of the Pull Request  
There are many build warnings now with like "cl : command line warning
D9047: option 'await' has been deprecated and will be re moved in a
future release." after we update to VS2026.

Introduce WinRT coroutine support by replacing `std::future` with
`IAsyncOperation` for asynchronous methods. Adjust output directories
and remove the `/await` option from project files to streamline the
build process. Update methods to utilize `std::expected` and `co_await`,
enhancing the async handling of version checks and downloads.

## PR Checklist  
- [ ] Closes: #xxx  
- [x] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [x] **Tests:** Added/updated and all pass  
- [ ] **Localization:** All end-user-facing strings can be localized  
- [ ] **Dev docs:** Added/updated  
- [ ] **New binaries:** Added on the required places  
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

## Detailed Description of the Pull Request / Additional comments  
Refactor async methods to improve performance and compatibility with
WinRT. The changes include modifying the return types of several
functions in the `updating` namespace, specifically
`uninstall_previous_msix_version_async`,
`get_github_version_info_async`, and `download_new_version_async`.

## Validation Steps Performed  
Manual testing was conducted to ensure that the new async methods
function correctly and that the application behaves as expected during
version checks and downloads. Automated tests were updated to cover the
new coroutine implementations.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/common/utils/HttpClient.h

@@ -1,6 +1,7 @@
 #pragma once
 
-#include <future>
+#include <functional>
+#include <string>
 #include <winrt/Windows.Foundation.h>
 #include <winrt/Windows.Storage.Streams.h>
 #include <winrt/Windows.Web.Http.h>
@@ -21,15 +22,15 @@ namespace http
             headers.UserAgent().TryParseAdd(USER_AGENT);
         }
 
-        std::future<std::wstring> request(const winrt::Windows::Foundation::Uri& url)
+        winrt::Windows::Foundation::IAsyncOperation<winrt::hstring> request(winrt::Windows::Foundation::Uri url)
         {
             auto response = co_await m_client.GetAsync(url);
             (void)response.EnsureSuccessStatusCode();
             auto body = co_await response.Content().ReadAsStringAsync();
-            co_return std::wstring(body);
+            co_return body;
         }
 
-        std::future<void> download(const winrt::Windows::Foundation::Uri& url, const std::wstring& dstFilePath)
+        winrt::Windows::Foundation::IAsyncAction download(winrt::Windows::Foundation::Uri url, std::wstring dstFilePath)
         {
             auto response = co_await m_client.GetAsync(url);
             (void)response.EnsureSuccessStatusCode();
@@ -38,7 +39,7 @@ namespace http
             file_stream.Close();
         }
 
-        std::future<void> download(const winrt::Windows::Foundation::Uri& url, const std::wstring& dstFilePath, const std::function<void(float)>& progressUpdateCallback)
+        winrt::Windows::Foundation::IAsyncAction download(winrt::Windows::Foundation::Uri url, std::wstring dstFilePath, std::function<void(float)> progressUpdateCallback)
         {
             auto response = co_await m_client.GetAsync(url, HttpCompletionOption::ResponseHeadersRead);
             response.EnsureSuccessStatusCode();