style: fix testimonial button hover color transition

Author: ASDAlexey

src/app/shared/components/testimonial-card/testimonial-card.scss

@@ -86,7 +86,7 @@
   border: 1px solid var(--border);
   border-radius: 999px;
   background: var(--bg-subtle);
-  color: var(--accent-light);
+  color: var(--text-secondary);
   cursor: pointer;
   transition:
     border-color 0.2s var(--ease),