fix(lsp): eglot-ensure advice nooping in some major modes

Due to the nested structure of eglot-server-programs, our advice would
not correctly detect entries for some modes (like javascript modes),
effectively disabling Eglot in those modes.

I've replaced the advice with a solution baked into lsp!, so folks still
have the option of using eglot-ensure directly if they want it activated
unconditionally.

Amend: #7219

modules/tools/lsp/+eglot.el

@@ -4,15 +4,6 @@
   :commands eglot eglot-ensure
   :hook (eglot-managed-mode . +lsp-optimization-mode)
   :init
-  (defadvice! +eglot--ensure-available-mode-a (fn)
-    "Run `eglot-ensure' if the current mode has support."
-    :around #'eglot-ensure
-    (when (alist-get major-mode eglot-server-programs nil nil
-                     (lambda (modes key)
-                       (if (listp modes)
-                           (member key modes)
-                         (eq key modes))))
-      (funcall fn)))
   (setq eglot-sync-connect 1
         eglot-autoshutdown t
         ;; NOTE: We disable eglot-auto-display-help-buffer because :select t in

modules/tools/lsp/autoload/common.el

@@ -5,6 +5,9 @@
   "Dispatch to call the currently used lsp client entrypoint"
   (interactive)
   (if (modulep! +eglot)
+      (when (require 'eglot nil t)
+        (if (eglot--lookup-mode major-mode)
             (eglot-ensure)
+          (eglot--message "No client defined for %s" major-mode)))
     (unless (bound-and-true-p lsp-mode)
       (lsp-deferred))))