ci: Treat compile warnings as errors (#4619)

* ci: Treat compile warnings as errors

* ci: Limit to compile commadn

Author: jcs090218

Eask

@@ -51,4 +51,7 @@
 
 (setq network-security-level 'low)  ; see https://github.com/jcs090218/setup-emacs-windows/issues/156#issuecomment-932956432
 
-(setq byte-compile-docstring-max-column 1000)
+(add-hook 'eask-before-compile-hook
+           (lambda ()
+             (setq byte-compile-error-on-warn t)
+             (setq byte-compile-docstring-max-column 1000)))