Remove unnecessary Sleep calls in tests.

[NullHypothesis]

As far as I can tell, these calls are not necessary and slow down our tests considerably. After removing the Sleep calls, I ran the test multiple times as follows:

go test \
    -race \
    -count=1 \
    -timeout 30s \
    -tags experimental \
    -run ^ExampleTimestampArray$ github.com/TileDB-Inc/TileDB-Go/examples

All tests passed, so we should be fine.

[thetorpedodog]

I think we still might want these to make sure these don’t land on the same millisecond (or at least to make it clear that they shouldn’t). Maybe reduce it to something like 5 * Millisecond instead?

[NullHypothesis]

I think we still might want these to make sure these don’t land on the same millisecond (or at least to make it clear that they shouldn’t). Maybe reduce it to something like 5 * Millisecond instead?

Right, I followed your suggestion in the follow-up commits.

[thetorpedodog]

one minor suggestion on the comment but looks good!

[thetorpedodog]

instead of "we are not going to overwrite the data" (which we want to do), it might be better to say "our writes are in different milliseconds to ensure correct ordering".