[x] Based your PR on the latest version of the correct branch (master or 4.x)
[x] Checked your writing carefully for correct English spelling, grammar, etc
[x] Described your changes and the motivation for them below
Description of Changes
Silences the new linkcheck failures due to Stack Overflow/Stack Exchange apparently blocking requests from GitHub Actions (likely due to scraping or bot concerns), and schedule the linkcheck job to run weekly to catch issues as they arise rather than just with PRs. Also, make the name clearer and allow running on-demand on workflow dispatch.
Pull Request
Pull Request Checklist
Description of Changes
Silences the new linkcheck failures due to Stack Overflow/Stack Exchange apparently blocking requests from GitHub Actions (likely due to scraping or bot concerns), and schedule the linkcheck job to run weekly to catch issues as they arise rather than just with PRs. Also, make the name clearer and allow running on-demand on workflow dispatch.
Unblocks PR #358