Expected Behavior

As a... Node Driver developer
I expect... driver to load correctly when `require` is available but dynamic-import callback is not
When... using driver 7.6 or higher

Actual Behavior and Impact

• Current experience: `MongoServerError: Missing required sub-document 'driver' in the client metadata document`
• This is incorrect and a red herring, forcing a user on a useless investigation
• Workaround: setting `runtimeAdapters: { os: require('os') }` as a connection option

Dependencies

• none

Risks/Unknowns

• none

Acceptance Criteria

Implementation Requirements

• update resolveRuntimeAdapters so it doesn't throw under environment where `require` is available, but the dynamic-import callback is not, like jest
•  `resolveRuntimeAdapters` resolves the default `os` adapter in a host that provides
  `require` but no dynamic-import callback.
• `resolveRuntimeAdapters` still resolves where `require` is absent or throws: real ESM,
  bundled ESM output, and the nodeless sandbox.
• A failure to build client metadata is no longer converted into an empty metadata document.

Testing Requirements

• add a new regression test that fails before the change
• new test must exercise a host that provides `require` but not a dynamic-import callback
• existing tests keep passing

Documentation Requirements

• none

Follow Up Requirements

• none

Old text

Some users (myself included) noticed a new error upon upgrading to client version `7.6.0`, namely: `MongoServerError: Missing required sub-document 'driver' in the client metadata document`.

This has been tracked down to [PR 4992](https://github.com/mongodb/node-mongodb-native/pull/4992) being the cause, with [this comment](https://github.com/mongodb/node-mongodb-native/pull/4992#issuecomment-5436379987) being the first one to report the issue.

Additionally, this has been reported to me at https://github.com/typegoose/mongodb-memory-server/issues/1026.

Workaround: set `runtimeAdapters: { os: require('os') }` as a connection option