Simplify watch WebSocket URL: always use ws:// since watch never serves HTTPS

fsdocs watch binds to HTTP only (no SSL certs), so window.location.protocol
can never be 'https:'. The wss: branch was dead code. Simplify to a direct
ws:// URI using window.location.host.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

src/fsdocs-tool/BuildCommand.fs

@@ -822,8 +822,7 @@ module Serve =
     let generateWatchScript () =
         """
 <script type="text/javascript">
-    var wsProtocol = window.location.protocol === "https:" ? "wss:" : "ws:";
-    var wsUri = wsProtocol + "//" + window.location.host + "/websocket";
+    var wsUri = "ws://" + window.location.host + "/websocket";
     function init()
     {
         websocket = new WebSocket(wsUri);