doc: fix broken link to TC39 import attributes proposal

The import assertion proposal has been renamed and, disappointingly,
the old URL does not redirect to the new one. So let's update our
URL to point to the import attributes proposal, which is what
import assertions have been renamed to.

doc/api/vm.md

@@ -1588,7 +1588,7 @@ are not controllable through the timeout either.
 [`Error`]: errors.md#class-error
 [`URL`]: url.md#class-url
 [`eval()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/eval
-[`optionsExpression`]: https://tc39.es/proposal-import-assertions/#sec-evaluate-import-call
+[`optionsExpression`]: https://tc39.es/proposal-import-attributes/#sec-evaluate-import-call
 [`script.runInContext()`]: #scriptrunincontextcontextifiedobject-options
 [`script.runInThisContext()`]: #scriptruninthiscontextoptions
 [`url.origin`]: url.md#urlorigin

test/fixtures/snapshot/typescript.js

@@ -135144,7 +135144,7 @@ var ts;
              *  import "foo" |
              * or after a re-export declaration that has a module specifier:
              *  export { foo } from "foo" |
-             * Source: https://tc39.es/proposal-import-assertions/
+             * Source: https://tc39.es/proposal-import-attributes/
              */
             if (contextToken) {
                 var file = contextToken.getSourceFile();