(jenkins-jobs) Allow customization of the "Discover fork pull requests" trait

[dduportal]

What feature do you want to see added?

Code at

helm-charts/charts/jenkins-jobs/templates/_helpers.tpl

Lines 213 to 218 in 8800432

	def traits = node / 'sources' / 'data' / 'jenkins.branch.BranchSource' / 'source' / 'traits'
	// Not discovered by Job-DSL: need to be configured as raw-XML
	traits << 'org.jenkinsci.plugins.github__branch__source.ForkPullRequestDiscoveryTrait' {
	strategyId(1) // 1-Merging the pull request with the current target branch revision
	trust(class: 'org.jenkinsci.plugins.github_branch_source.ForkPullRequestDiscoveryTrait$TrustPermission')
	}

is:

• Not customizable (we want to disable PR from forks on some jobs on infra.ci.jenkins.io for instance)
• Tedious as it does not use the native JobDSL keyword (this code was written 2 years ago: worth checking if the JobDSL plugin has recent native support like (jenkins-jobs) Allow customization of the "Discover origin pull requests" trait #1211)

Upstream changes

No response