Why was the 'environment' field removed?

Because it's invalid, not supported.

I’m not sure where you got this information, but this change would break our release workflow.

https://docs.github.com/en/actions/how-tos/write-workflows/choose-what-workflows-do/deploy-to-environment#using-an-environment-in-a-workflow

In any case, please don’t modify our release workflow without providing some context or explanation. Without that, this PR can come across as suspicious and may raise unnecessary concerns.

I understand. I will put it back, but it is still invalid according to:

• https://www.schemastore.org/github-workflow.json
• https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#jobsjob_idenvironment

https://www.schemastore.org/github-workflow.json is not official and can be wrong.

I see. Sorry about that. Reverted.

How about using camelCase instead

Because of this code further down:

        BASIC_KEYS.forEach((key) => {
          const val = options[key];
          if (val !== undefined) {
            Object.assign(meta, getMeta(`og:${key}`, val));
          }
        });

It would require a rewrite, which I find too risky.

I still prefer to use camelCase in our public API

Okay, I will rename and rewrite.

Done, added a small toSnakeCase function so that siteName becomes site_name