[prebuilds] ignore inverse PRs

[svenefftinge]

Description

This change ignores inverse PRs, such as they are created by pull bots.

Related Issue(s)

Fixes https://github.com/gitpod-io/security/issues/26

How to test

• Install webhook or GH App on a repo.
• Create a fork
• Push to the main repo
• Create a PR in the fork that wants to update the fork

In prod a prebuild would be created and overwrite the original prebuild from the main repo. With this change no such prebuild should be created anymore.

Release Notes

NONE

• /werft with-vm

[svenefftinge]

/werft run

👍 started the job as gitpod-build-se-no-inverse-prs.2
(with .werft/ from main)

[svenefftinge]

/werft run with-clean-slate-deployment=true

👍 started the job as gitpod-build-se-no-inverse-prs.3
(with .werft/ from main)

[geropl]

@jankeromnes Could you take a look here as well? 🙏

[svenefftinge]

/werft run with-vm=true

👍 started the job as gitpod-build-se-no-inverse-prs.4
(with .werft/ from main)

[svenefftinge]

/werft run with-vm=true

👍 started the job as gitpod-build-se-no-inverse-prs.5
(with .werft/ from main)

[svenefftinge]

/werft run with-clean-slate-deployment=true

👍 started the job as gitpod-build-se-no-inverse-prs.6
(with .werft/ from main)

[svenefftinge]

/werft run with-clean-slate-deployment=true

👍 started the job as gitpod-build-se-no-inverse-prs.8
(with .werft/ from main)

[svenefftinge]

/werft run with-clean-slate-deployment=true

👍 started the job as gitpod-build-se-no-inverse-prs.9
(with .werft/ from main)

[svenefftinge]

/werft run with-clean-slate-deployment=true

👍 started the job as gitpod-build-se-no-inverse-prs.10
(with .werft/ from main)

[mustard-mh]

@svenefftinge run /werft with-vm=true /werft run with-vm=true will work, but you need to rebase to a9ae750 first, because this commit f5778fa is incompatible with harvester

[svenefftinge]

/werft with-vm=true

👎 unknown command: with-vm=true
Use /werft help to list the available commands

[svenefftinge]

/werft run with-vm=true

👍 started the job as gitpod-build-se-no-inverse-prs.12
(with .werft/ from main)

[svenefftinge]

/werft run with-vm=true

👍 started the job as gitpod-build-se-no-inverse-prs.13
(with .werft/ from main)

[mustard-mh]

but you need to rebase to a9ae750 first, because this commit f5778fa is incompatible with harvester

@svenefftinge FYI, rebase via

git rebase --onto=a9ae750610a786adb8306229b123294ec44f9b6c HEAD~1

[csweichel]

@svenefftinge can we remove the hold and get this merged?