fix build errors

src/Umbraco.Web.Common/Extensions/EndpointRouteBuilderExtensions.cs

@@ -15,7 +15,7 @@ namespace Umbraco.Extensions
             this IEndpointRouteBuilder endpoints,
             Type controllerType,
             string rootSegment,
-            string areaName,
+            string? areaName,
             string? prefixPathSegment,
             string defaultAction = "Index",
             bool includeControllerNameInRoute = true,
@@ -57,7 +57,7 @@ namespace Umbraco.Extensions
 
                     // named consistently
                     $"umbraco-{areaName}-{controllerName}".ToLowerInvariant(),
-                    areaName,
+                    areaName!,
                     pattern.ToString().ToLowerInvariant(),
                     defaults,
                     constraints);
@@ -98,7 +98,7 @@ namespace Umbraco.Extensions
         /// </summary>
         public static void MapUmbracoApiRoute(
             this IEndpointRouteBuilder endpoints,
-            Type? controllerType,
+            Type controllerType,
             string rootSegment,
             string? areaName,
             bool isBackOffice,

src/Umbraco.Web.Common/Extensions/ViewDataExtensions.cs

@@ -47,7 +47,7 @@ namespace Umbraco.Extensions
             if (!hasCookie) return false;
 
             // get the cookie value
-            if (!httpContext.Request.Cookies.TryGetValue(cookieName, out var cookieVal))
+            if (httpContext is null || !httpContext.Request.Cookies.TryGetValue(cookieName, out var cookieVal))
             {
                 return false;
             }

src/Umbraco.Web.Common/ModelsBuilder/ModelsBuilderNotificationHandler.cs

@@ -57,7 +57,7 @@ namespace Umbraco.Cms.Web.Common.ModelsBuilder
                 throw new ArgumentException("Null umbracoUrls");
             }
 
-            if (!(umbracoUrlsObject is Dictionary<string, object> umbracoUrls))
+            if (!(umbracoUrlsObject is Dictionary<string, object?> umbracoUrls))
             {
                 throw new ArgumentException("Invalid umbracoUrls");
             }