Fix compilation warning in gptel-openai.el

* gptel-openai.el (cl-lib): Require it.

* gptel.el (compat): Leniently require compat so gptel.el can be
compiled standalone.  This will expose other compiler errors that
are easily visible with M-x flymake.

Author: joaotavora

gptel-openai.el

@@ -23,6 +23,8 @@
 
 ;;; Code:
 (require 'cl-generic)
+(eval-when-compile
+  (require 'cl-lib))
 (require 'map)
 
 (defvar gptel-model)

gptel.el

@@ -120,7 +120,7 @@
 (eval-when-compile
   (require 'subr-x)
   (require 'cl-lib))
-(require 'compat)
+(require 'compat nil t)
 (require 'url)
 (require 'json)
 (require 'map)