MINOR: [CI] Bump actions/download-artifact from 4.2.1 to 6.0.0#76

dependabot[bot] wants to merge 1 commit into5588-Better-support-for-building-UnionArraysQuietCraftsmanship/arrow:5588-Better-support-for-building-UnionArraysfrom

dependabot/github_actions/actions/download-artifact-6.0.0QuietCraftsmanship/arrow:dependabot/github_actions/actions/download-artifact-6.0.0Copy head branch name to clipboard