[BUGFIX] Scraping: Tolerance should be max 1% of interval

[bboreham]

Previous code set it at minimum 1%, which was not intended.

Fixes #13730

[machine424]

Thanks,
I think we should update

prometheus/cmd/prometheus/main.go

Line 426 in 3d16d39

a.Flag("scrape.timestamp-tolerance", "Timestamp tolerance. See https://github.com/prometheus/prometheus/issues/7846 for more context. Experimental. This flag will be removed in a future release.").

to mention that we go with 1% of the interval now (and we no longer skip as before.)

[machine424]

But we didn't mention that alignments were skipped if the tolerance is greater than 1% of the scrape interval, so we can keep it like that. Your call.

[bboreham]

The docstring didn't explain much before, so I don't feel it's essential to improve it in this PR.
Maybe we could do a subsequent PR that takes the feature out of experimental status, and documents it clearly.