(jenkins-jobs) Allow customization of the "Branch Discovery" trait

[dduportal]

What feature do you want to see added?

Code in

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

Lines 152 to 154 in 8800432

	gitHubBranchDiscovery {
	strategyId(1) // 1-only branches that are not pull requests
	}

is not customizable.

We want to specify jobs without branch discovery, only PRs (infra.ci: website deployments and infra-report PR test builds for instance)

Upstream changes

No response