Update `sqllogittest` workflow run to be less frequent

[rampage644]

With the merging of #869, the sqllogictest workflow now executes on every commit to the main branch (upon merging each PR). However, not all PRs lead to changes in the compatibility numbers. Typically, there are around 5–7 daily commits that don’t materially affect compatibility artifacts, resulting in redundant test executions.

It would be beneficial to adjust the trigger accordingly. Perhaps running this workflow nightly (once per day) instead of multiple times daily could be an efficient approach to consider initially.

[andheroe]

We have recently implemented a developer's request - ability to compare local tests results with results from the main branch - to see improvements/regressions.
If we don't run all tests on each merge to main - this feature won't work correctly. I assume that our team can do multiple changes to the Engine per day, and developers won't be comparing test results to the most up to date test results on main.
I would also prefer the coverage results in the readme of our repo to be always up to date.
What do you think? How big of a problem frequent SLT runs is now? Running all SLTs takes around 3 minutes.