[proj. name] - Enable and tune Dependabot tool

[rozhukov]

1. Enable Depenabot in Settings -> Code Security
2. Minimal recommended settings:
   • Dependabot alerts - ON
   • Dependabot security updates - ON
   • Grouped security updates - ON

More info: https://docs.github.com/en/code-security/dependabot/dependabot-security-updates/configuring-dependabot-security-updates