chore: Introduce Dependabot workflow

[daogrady]

I noticed during install that we have deprecated dependencies:

npm warn deprecated puppeteer@23.11.1: < 24.15.0 is no longer supported

which is due to:

➜  npm ls puppeteer@23.11.1
@cap-js/openapi@1.3.0 /openapi
└─┬ @mermaid-js/mermaid-cli@11.12.0
  └── puppeteer@23.11.1

we should be notified of outdated dependencies automatically.