processors/github_metadata: gather pushed_at instead of updated_at

[nodiscc]

updated_at seems to reflect the date of last change (description, issues, comments, PRs, ...) to a repository, but we want the date of last commit to the default branch.

Use pushed_at? (the meaning of API responses fields is not clearly documented).

Followup to https://github.com/awesome-selfhosted/awesome-selfhosted/pull/3183

Related https://github.com/nodiscc/hecat/issues/48, the same behaviour is needed for Gitlab projects.

/cc @KieranRobson

[Ki-er]

Since updated_at will take issues made and prs created as updated, pushed_at may be the better choice since the last commit, however the two that marked as 2016 within https://github.com/awesome-selfhosted/awesome-selfhosted/pull/3183 actually showed as 2019 within the commit check script. It was only after I checked for myself on the repo did I see the last commit date as 2016

[nodiscc]

Change made in https://github.com/nodiscc/hecat/pull/55, by consequence the number of warnings about stale projects has increased by many: https://github.com/nodiscc/hecat/runs/7672422797?check_suite_focus=true#step:3:867

[nodiscc]

There is still something going on with updated_at/pushed_at, it does not reflect the actual time of the last commit, see https://github.com/awesome-selfhosted/awesome-selfhosted/pull/3403. Reopening.

[nodiscc]

https://api.github.com/repos/ZizzyDizzyMC/linx-server: pushed_at | "2022-06-27T14:43:35Z" but the latest commit https://github.com/ZizzyDizzyMC/linx-server/commits/master is from 2021-12-24...

There is no mention of 2021-12-24 anywhere in the API response.

• https://stackoverflow.com/questions/15918588/github-api-v3-what-is-the-difference-between-pushed-at-and-updated-at
• https://github.com/react-native-community/directory/issues/20

[nodiscc]

Ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/3499

/cc @sarmong