fix db.close() for new interface

[kbkpbot]

As PR (vlang/v#24780) modify the db close() to using the pool interface.

[medvednikov]

Should this be merged after the V fix?

Error: src/main.v:28:14: error: unexpected or block, the function close does not return an Option or a Result
26 |
27 | defer {
28 | db.close() or {}
| ~~~~~
29 | }

[JalonSolov]

Should this be merged after the V fix?

Error: src/main.v:28:14: error: unexpected or block, the function close does not return an Option or a Result 26 | 27 | defer { 28 | db.close() or {} | ~~~~~ 29 | }

Classic chicken/egg problem. This won't pass the CI clean until V is updated, but V won't pass CI clean until this is updated.