chore(ci): add main branch build workflow and concurrency control

[gnodet]

Summary

• Add main-build.yml workflow for push builds on main and release branches (camel-4.10.x, camel-4.14.x) with JDK 21
• Add concurrency groups with cancel-in-progress: true to PR workflows (pr-build-main, depsreview, pr-doc-validation, pr-id) so outdated CI runs are automatically cancelled when a PR is updated

Supersedes #20226 (rebased onto current main with updated action versions and JDK 17 dropped).

Test plan

• CI passes on this PR
• Verify concurrency groups cancel previous runs on PR update
• Verify main-build workflow triggers on push to main

🤖 Generated with Claude Code

[github-actions]

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[Croway]

camel-4.18.x is missing, I think camel-4.10.x should be replaced with camel-4.18.x, I just did something similar to the jenkinsfiles, maybe the same need to be done on the GitHub

[davsclaus]

yeah 4.10 is EOL