Statistics: retrieve all merged commits and authors

[Neradoc]

When retrieving the merged Pull Requests for weekly stats, only around 30 were retrieved on the core repository due to the default pagination of the results. But there is more than 100 issues and PRs updated every week these days, so a lot of them were missing.

The code to retrieve the opened pull requests already went through all the pages (using the 100 items per page max of the API), so I factored it out as a convenience function and used it in both places. Also the additional pages are now always retrieved with the github_requests module, avoiding a few hits to the unauthenticated rate limit (I think these were the last ones).

before (last weekly meeting notes)

Overall

• 40 pull requests merged
  • 22 authors - jfurcean, hugodahl, dherrada, JPEWdev, tannewt, thefloe1, lyusupov, m-byte, sabas1080, bergdahl, kmatch98, tyomitch, jposada202020, askpatrickw, FoamyGuy, weblate, dhalbert, jamesrusso, jepler, ryang14, makermelissa, ladyada
  • 8 reviewers - kattni, gamblor21, FoamyGuy, dhalbert, tannewt, jepler, makermelissa, ladyada
• 20 closed issues by 11 people, 22 opened by 16 people

after (today)

Overall

• 61 pull requests merged
  • 29 authors - m-byte, jposada202020, sabas1080, dhalbert, JPEWdev, weblate, thefloe1, microDev1, ZodiusInfuser, pdp7, Neradoc, t-ikegami, hugodahl, jepler, tyomitch, UnexpectedMaker, kmatch98, lesamouraipourpre, bergdahl, ladyada, mebs, tannewt, wtuemura, hathach, FoamyGuy, fharding1, ryang14, makermelissa, dlizotte-uwo
  • 10 reviewers - microDev1, dhalbert, brentru, ladyada, hierophect, tannewt, FoamyGuy, gamblor21, makermelissa, jepler
• 40 closed issues by 12 people, 32 opened by 21 people

[tannewt]

Great find! I feel bad we've been missing activity for so long. Thanks for looking into this!