chore: add changeset for stylelint-order v8 and stylelint-gamut v2

Author: Kael

.changeset/major-dep-bumps.md

@@ -0,0 +1,6 @@
+---
+"@benhigham/stylelint-config": minor
+---
+
+- Bump `stylelint-order` from v7 to v8 — adds CSS-in-JS interpolation autofix support; no config changes required
+- Bump `stylelint-gamut` from v1 to v2 — migrated to ESM, adds Stylelint v17 support; no config changes required