Duplicate runs between (applied, force-pushed upstream commit) pull requests and main branch

[john-tho]

Situation was: Pull request (PR) open, ready to merge https://github.com/openwrt/openwrt/pull/13021

Guessing process: Maintainer picked and applied PR commit, and pushed to git.openwrt.org Maintainer force-pushed (upstream) commit to PR fork branch, for github bot to mark merged PR. This triggered CI runs for PR / fork:

• https://github.com/openwrt/openwrt/actions/runs/5457230379 (core packages)
• https://github.com/openwrt/openwrt/actions/runs/5457230382 (host tools)
• https://github.com/openwrt/openwrt/actions/runs/5457230384 (kernel)

Github OpenWrt mirror has picked up the git.openwrt.org changes, and started duplicate CI runs:

• https://github.com/openwrt/openwrt/actions/runs/5457231805 (core packages)
• https://github.com/openwrt/openwrt/actions/runs/5457231807 (kernel) was cancelled for higher priority main commits
• https://github.com/openwrt/openwrt/actions/runs/5457231812 (host tools)

Both these sets of CI actions ran on https://github.com/openwrt/openwrt/commit/b3448b3fdb59d25dce05991dc8f322c1020b090b, the first via the PR / fork. Duplicate usage time was over six hours.

Ideally we detect when a CI run has triggered on an identical git tree state to avoid this. Choices around what we do here (cancel the PR run?), given different branches can have different actions.

Cheers