[PM-29224] Remove unused billing endpoints and code paths (#6692)

* Remove unused endpoints and code paths

* MOAR DELETE

* Run dotnet format

src/Api/Billing/Controllers/VNext/SelfHostedAccountBillingVNextController.cs

@@ -0,0 +1,37 @@
+using Bit.Api.Billing.Attributes;
+using Bit.Api.Billing.Models.Requests.Premium;
+using Bit.Api.Utilities;
+using Bit.Core;
+using Bit.Core.Billing.Models.Business;
+using Bit.Core.Billing.Premium.Commands;
+using Bit.Core.Entities;
+using Bit.Core.Exceptions;
+using Bit.Core.Utilities;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+
+namespace Bit.Api.Billing.Controllers.VNext;
+
+[Authorize("Application")]
+[Route("account/billing/vnext/self-host")]
+[SelfHosted(SelfHostedOnly = true)]
+public class SelfHostedAccountBillingVNextController(
+    ICreatePremiumSelfHostedSubscriptionCommand createPremiumSelfHostedSubscriptionCommand) : BaseBillingController
+{
+    [HttpPost("license")]
+    [RequireFeature(FeatureFlagKeys.PM24996ImplementUpgradeFromFreeDialog)]
+    [InjectUser]
+    public async Task<IResult> UploadLicenseAsync(
+        [BindNever] User user,
+        PremiumSelfHostedSubscriptionRequest request)
+    {
+        var license = await ApiHelpers.ReadJsonFileFromBody<UserLicense>(HttpContext, request.License);
+        if (license == null)
+        {
+            throw new BadRequestException("Invalid license.");
+        }
+        var result = await createPremiumSelfHostedSubscriptionCommand.Run(user, license);
+        return Handle(result);
+    }
+}