Show smaller time interval on PRs

[gs0510]

Sometimes changes to benchmarks might be made but since the data is immutable, it shows up as NA. If we load smaller data from the database, this problem of displaying dead benchmarks will go away.

Index benchmarks introduced a change and the PR shows the data for the dead metric as well.

[punchagan]

Are we talking about the main branch or PRs here? It looks like PRs no longer show metrics that have been removed on the branch. But, graphs on the main branch do show all the metrics, even if one or two metrics are removed from the latest commit.