chore(ci): optimize workflows to reduce unnecessary runs

[mandarini]

• Add paths-ignore to publish.yml to skip releases for markdown/docs changes
• Add concurrency groups to PR workflows to auto-cancel outdated runs
• Configure conditional cancellation (PRs only, not workflow_call from master)

This reduces CI resource usage by:

• Preventing CI on master triggered by CHANGELOG/docs updates
• Cancelling stale PR runs when new commits are pushed
• Preserving master workflow runs for proper release flow

[coveralls]

coverage: 96.027% (+0.04%) from 95.986%
when pulling bb228e0 on chore/exclude-md-files
into 7caf82e on master.