fix: drop SAP statement after prepare per Hana client docs

[imnotjames]

Description of change

each statement takes up a pool so if you query frequently you can
exhaust that pool of statement handles. this drops the statement
after we're done with it so we don't exhaust the pool of statements

fixes #7344

Pull-Request Checklist

• Code is up-to-date with the master branch
• npm run lint passes with this change
• npm run test passes with this change
• This pull request links relevant issues as Fixes #0000
• There are new or updated unit tests validating the change
• Documentation has been updated to reflect this change
• The new commits follow conventions explained in CONTRIBUTING.md

[imnotjames]

unfortunately, we still don't test SAP Hana. I can barely get a server running to execute tests. Based off the documentation this seems reasonable, though?

[pleerock]

Any additional test infrustructure is highly appreciated 🤞

[imnotjames]

SAP Hana is very, very hard to get testing because of the licensing around Hana. It used to be easier but SAP restricted it further.

It now requires an account that has "purchased" the development kit for free in docker hub. This can be done but it requires attention any time a new version is released.

It also caused the CI runner to OOM in my tests.