Add defensive window.document check when checking for startViewTransition (remix-run#11544)

Co-authored-by: Nathan Rajlich <[email protected]>

Author: 2 people

.changeset/good-donkeys-kiss.md

@@ -0,0 +1,5 @@
+---
+"react-router-dom": patch
+---
+
+Check for `document` existence when checking `startViewTransition`

contributors.yml

@@ -242,6 +242,7 @@
 - tlinhart
 - tom-sherman
 - tomasr8
+- TooTallNate
 - triangularcube
 - trungpv1601
 - turansky

packages/react-router-dom/index.tsx

@@ -526,6 +526,7 @@ export function RouterProvider({
 
       let isViewTransitionUnavailable =
         router.window == null ||
+        router.window.document == null ||
         typeof router.window.document.startViewTransition !== "function";
 
       // If this isn't a view transition or it's not available in this browser,