fix: Add mongo heartbeatEnabled param to tracer entrypoint

[jeancornic]

What does this PR do?

This PR intends to fix the newly added heartbeatEnabled parameter for the mongo plugin.

Motivation

While the parameter is used in the plugin's code, I cannot use it as is in the tracer config, because of the missing typing.

error TS2353: Object literal may only specify known properties, and 'heartbeatEnabled' does not exist in type 'mongodb_core'

Additional Notes

Follows #5526 and #5562

[BridgeAR]

@jeancornic thank you for the PR! We intend to move more to environment variable usage instead of programmatic one. That allows this to later on also be defined from a remote source.
Is there a reason not to use the DD_TRACE_MONGODB_HEARTBEAT_ENABLED environment variable and setting it to 'false'?

[Edit] I guess we should support it, due to already providing the programmatic API. So adding the TS code is good. We must port the PR though, to be opened by a maintainer. Otherwise we can't run our CI.

[cit-pr-commenter]

PR Security Update

All commits in this PR up to and including 32535a1 have been reviewed and marked safe by SDLC security. For any questions, please reach out to #ci-for-external-contributors-collab on Slack.

[jeancornic]

@BridgeAR thanks for your answer!
I ended up using the env variable yes, no worries. I was just surprised though by the code supporting a config parameter that is in the end not usable.

Cheers from an ex DD 🐶