chore(stepper): update default variant, key focus state in s2 (#3594)

Updates Stepper's key-focus border color (`--spectrum-stepper-border-color-keyboard-focus`) to `--spectrum-gray-800`.

---------

Co-authored-by: [ Cassondra ] <[email protected]>

Author: TarunAdobe

.changeset/shaggy-dragons-visit.md

@@ -0,0 +1,5 @@
+---
+"@spectrum-css/stepper": patch
+---
+
+Updates Stepper's key-focus border color (`--spectrum-stepper-border-color-keyboard-focus`) to `--spectrum-gray-800`.

components/stepper/themes/spectrum-two.css

@@ -18,7 +18,7 @@
 		--spectrum-stepper-border-color-hover: var(--spectrum-gray-600);
 		--spectrum-stepper-border-color-focus: var(--spectrum-gray-800);
 		--spectrum-stepper-border-color-focus-hover: var(--spectrum-gray-800);
-		--spectrum-stepper-border-color-keyboard-focus: var(--spectrum-gray-900);
+		--spectrum-stepper-border-color-keyboard-focus: var(--spectrum-gray-800);
 
 		--spectrum-stepper-buttons-border-style: none;
 		--spectrum-stepper-buttons-border-width: 0;