bug #7231 Fix colors not applied on button disable state (Julien Richarte)

This PR was squashed before being merged into the 4.x branch.

Discussion
----------

Fix colors not applied on button disable state

Hi, fix this issue : #7217

Commits
-------

2ad0932 Fix colors not applied on button disable state

Author: javiereguiluz

assets/css/easyadmin-theme/buttons.css

@@ -210,6 +210,9 @@
 /* Disabled state */
 .btn.disabled,
 .btn:disabled {
+    background: var(--button-active-bg, var(--button-bg));
+    border-color: var(--button-active-border-color, var(--button-border-color));
+    color: var(--button-active-color, var(--button-color));
     box-shadow: none;
     cursor: not-allowed;
     opacity: var(--button-disabled-opacity);