Add `'pre-authorized_grant_anonymous_access_supported': true`.

[dlongley]

Addresses #75.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 85.91%. Comparing base (9d82284) to head (7bf0e90).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #76 +/- ## ========================================== + Coverage 85.90% 85.91% +0.01% ========================================== Files 11 11 Lines 2753 2755 +2 ========================================== + Hits 2365 2367 +2 Misses 388 388 ``` | [Files](https://app.codecov.io/gh/digitalbazaar/bedrock-vc-delivery/pull/76?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar) | Coverage Δ | | |---|---|---| | [lib/openId.js](https://app.codecov.io/gh/digitalbazaar/bedrock-vc-delivery/pull/76?src=pr&el=tree&filepath=lib%2FopenId.js&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar#diff-bGliL29wZW5JZC5qcw==) | `86.75% <100.00%> (+0.02%)` | :arrow_up: | ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/digitalbazaar/bedrock-vc-delivery/pull/76?dropdown=coverage&src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/digitalbazaar/bedrock-vc-delivery/pull/76?dropdown=coverage&src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar). Last update [9d82284...7bf0e90](https://app.codecov.io/gh/digitalbazaar/bedrock-vc-delivery/pull/76?dropdown=coverage&src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=digitalbazaar).