Grant push permissions to Benchmark.yml

[penelopeysm]

@yebai I'm cautiously optimistic this might work :)

[yebai]

Thanks, @penelopeysm -- works like a charm!

[yebai]

@penelopeysm it seems like https://github.com/TuringLang/AdvancedVI.jl/actions/runs/10791262052/job/29928290483 failed again, even after incorporating changes from this PR.

[penelopeysm]

Oh, I keep getting caught out by this. It's probably because that PR is coming from a fork, and github won't give that PR permission to push to a branch.

[yebai]

Thanks, @penelopeysm. Can you modify the benchmarks CI to skip uploading for PRs from forks?

@Red-Portal can you create branches from this repo in the future so we don't run into Ci permission issues?

[Red-Portal]

Thank you all for the work. I'll do it the suggested way in the future. Though external PRs will probably suffer from the permission issues still.

[penelopeysm]

Hmmm. I just got a chance to look at it a bit more closely. My inclination is that the workflow should only push to gh-pages for commits that are on the main branch?

Otherwise, if we update the benchmark JSON file for every PR/commit, the regression test (alert-threshold > 200%) won't run against main, but rather against whichever commit someone else last pushed.