Update the ESLint globals list (PR 17055 follow-up)

Given that we only use standard `import`/`export` statements now, after recent PRs, the "exports" global is unused.
Instead we add "__non_webpack_import__" to the `globals` to avoid having to sprinkle disable statements throughout the code.

Finally, the way that `globals` are defined has changed in ESLint and we should thus explicitly specify them as "readonly"; please find additional details at https://eslint.org/docs/latest/use/configure/language-options#specifying-globals

src/display/api.js

@@ -2306,7 +2306,7 @@ class PDFWorker {
       const worker =
         typeof PDFJSDev === "undefined"
           ? await import("pdfjs/pdf.worker.js")
-          : await __non_webpack_import__(this.workerSrc); // eslint-disable-line no-undef
+          : await __non_webpack_import__(this.workerSrc);
       return worker.WorkerMessageHandler;
     };