Fix color of disabled dropdown-item (#2052)

Co-authored-by: Paweł Kuna <1282324+codecalm@users.noreply.github.com>

.changeset/good-birds-smash.md

@@ -0,0 +1,5 @@
+---
+"@tabler/core": patch
+---
+
+Fix `color` of disabled `dropdown-item` in Navbar component

src/scss/layout/_navbar.scss

@@ -40,7 +40,7 @@
         color: inherit;
 
         &.disabled {
-          color: var(--#{$prefix}gray-300);
+          color: var(--#{$prefix}disabled-color);
           pointer-events: none;
           background-color: transparent;
         }