Fix invalid generated CSS (HDS-5314) (#3131)

Co-authored-by: Cristiano Rastelli <cristiano.rastelli@hashicorp.com>

Author: KristinLBradley

.changeset/mighty-masks-wave.md

@@ -0,0 +1,15 @@
+---
+"@hashicorp/design-system-components": patch
+---
+
+<!-- START components/button -->
+`Button` - Removed CSS declaration for pseudo element in disabled state
+<!-- END -->
+
+<!-- START components/dropdown -->
+`Dropdown` - Removed CSS declaration for pseudo element in disabled state
+<!-- END -->
+
+<!-- START components/form/file-input -->
+`FileInput` - Removed CSS declaration for pseudo element in disabled state that led to invalid CSS (ignored by browsers)
+<!-- END -->

packages/components/src/styles/mixins/_button.scss

@@ -84,10 +84,6 @@ $hds-button-size-props: (
   border-color: var(--token-color-border-primary);
   box-shadow: none;
   cursor: not-allowed;
-
-  &::before {
-    border-color: transparent;
-  }
 }
 
 @mixin hds-button-state-focus() {