chore(github-actions) : Fixes notify-failed-actions workflow

[aialok]

Closes: #737

Summary:

• When any workflow fails, this workflow will notify about the failed workflow on GitHub Actions.

Notes:

• There might be a need to change the Slack webhook URL because this workflow should notify only on the Slack GitHub channel.
• Also, this workflow is using secrets for the webhook URL, while other workflows need to be updated to use secrets instead of vars.

Do you think resolving this issue might require an Architectural Decision Record (ADR)? (significant or noteworthy)

No
[No justification required as the change does not appear to be architecturally significant.]

[benjagm]

Lookas good. Thanks Alok