`temporal-utils` is incompatible with CJS

[connor-baer]

Relates to #99 and #62.

Thanks for fixing the export conditions for temporal-polyfill in v1.0.3 to support requiring from CJS. Unfortunately, temporal-utils has a similar issue that can likely be fixed in the same way.

I ran into this issue when testing code that depends on temporal-polyfill with Jest (v30.4). I get the following error:

Cannot find module 'temporal-utils/protected' from '../../../node_modules/temporal-polyfill/chunks/internal.js'

    Require stack:
      /<redacted>/node_modules/temporal-polyfill/chunks/internal.js
      /<redacted>/node_modules/temporal-polyfill/chunks/classApi-basic.js
      /<redacted>/node_modules/temporal-polyfill/index.js
      ...

Manually editing the package.json#exports config for temporal-utils to use the same format as temporal-polyfill fixes the issue:

"exports": {
    ".": {
      "types": "./dist/index.d.ts",
-      "import": "./dist/index.js"
+      "default": "./dist/index.js"
    },
    "./protected": {
      "types": "./dist/protected.d.ts",
-      "import": "./dist/protected.js"
+      "default": "./dist/protected.js"
    },
    "./protected-error-messages": {
      "types": "./dist/protected-error-messages.d.ts",
-      "import": "./dist/protected-error-messages.js"
+      "default": "./dist/protected-error-messages.js"
    }
  },

I'll open a pull request in a few minutes.