feat: notify slack on gh action workflows failure

[cka-y]

Summary: This pull request updates the Slack notification action and integrates it into various GitHub workflows to send priority-based alerts on failure. It also includes documentation updates for the workflows.

Updates to Slack Notification Action:

• Enhanced the Slack notification action to send alerts based on priority levels with an optional step description. (.github/actions/notify-slack/action.yml)

Integration of Slack Notifications into Workflows:

• Added notify-slack-on-failure job to multiple workflows to send Slack notifications on failure:
  • datasets-batch-deployer-dev.yml
  • db-update-dev.yml
  • db-update-prod.yml
  • db-update-qa.yml
  • release-qa.yml
  • release.yml
  • validator-update.yml

Documentation Updates:

• Added a comprehensive table documenting all GitHub workflows, including descriptions, triggers, dependencies, and Slack notification settings. (docs/GitHubWorkflows.md) Summarize the changes in the pull request including how it relates to any issues (include the #number, or link them).

Expected behavior:

Please make sure these boxes are checked before submitting your pull request - thanks!

• [x] Run the unit tests with ./scripts/api-tests.sh to make sure you didn't break anything
• [x] Add or update any needed documentation to the repo
• [x] Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• [x] Linked all relevant issues
• [x] Include screenshot(s) showing how this pull request works and fixes the issue(s)