fix(linter/plugins): define RegExp.escape for tsc

Author: overlookmotel

apps/oxlint/src-js/globals.d.ts

@@ -5,3 +5,9 @@ declare const DEBUG: boolean;
 
 // `true` if is build for conformance testing
 declare const CONFORMANCE: boolean;
+
+// `RegExp.escape` is not yet in TypeScript's lib types (available from ES2025).
+// TODO: Remove this once TypeScript ships it.
+interface RegExpConstructor {
+  escape(str: string): string;
+}