Keep Prettier at 3.8.3 to match Super-Linter

Prettier 3.9 formats a union type in src/core/types.ts differently from
the Prettier bundled in Super-Linter v8.7.0, so the two checks can't both
pass. Revert the Prettier bump and the reformat.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013sSVPq8jM5vj3VFsnBEGPn

Author: claude

package-lock.json

@@ -80,7 +80,7 @@
     "eslint-plugin-prettier": "^5.5.6",
     "jest": "^30.5.2",
     "parse-glob": "3.0.4",
-    "prettier": "3.9.9",
+    "prettier": "3.8.3",
     "rimraf": "^6.1.3",
     "rollup": "4.64.3",
     "typescript": "^6.0.3"

package.json

@@ -27,7 +27,10 @@ export interface Ruleset {
   'href-abs-or-rel'?: 'abs' | 'rel'
   'id-class-ad-disabled'?: boolean
   'id-class-value'?:
-    'underline' | 'dash' | 'hump' | { regId: RegExp; message: string }
+    | 'underline'
+    | 'dash'
+    | 'hump'
+    | { regId: RegExp; message: string }
   'id-unique'?: boolean
   'inline-script-disabled'?: boolean
   'inline-style-disabled'?: boolean