build: update stylelint usage to use unit-allowed-list (#20617)

Update the stylelint config file to use unit-allowed-list

(cherry picked from commit 57e32e9)

Author: josephperrott

.stylelintrc.json

@@ -47,7 +47,7 @@
 
     "unit-case": "lower",
     "unit-no-unknown": true,
-    "unit-whitelist": ["px", "%", "deg", "s", "ms", "em", "vh", "vw", "vmin"],
+    "unit-allowed-list": ["px", "%", "deg", "s", "ms", "em", "vh", "vw", "vmin"],
 
     "value-list-comma-space-after": "always-single-line",
     "value-list-comma-space-before": "never",