woodpecker: Don't fail on missing CI config

Component

server

Describe the bug

Not necessarily all branches of a repository are intended to have a CI config. But branches without a CI config will always create an error in the UI.

In the past, I was able to work around this issue by adding [skip ci] to all commits to branches without a CI config. This is now also broken, see https://github.com/woodpecker-ci/woodpecker/pull/2216.

My suggestion would be to simply ignore missing CI configurations, or at least not create a failed pipeline in the UI. Alternatively, users should have the option to ignore branches. A common example would be github-pages branches, where only page artifacts are published and no CI configuration.

System Info

{"source":"https://github.com/woodpecker-ci/woodpecker","version":"next-06d1f3c92e"}

Additional context

No response

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn’t already an issue that reports the same bug to avoid creating a duplicate.
• Checked that the bug isn’t fixed in the next version already [https://woodpecker-ci.org/faq#which-version-of-woodpecker-should-i-use]
• Check that this is a concrete bug. For Q&A join our Discord Chat Server or the Matrix room.