Dependencies: Add dependabot to the repo

[lsr-explore]

Updates are currently being managed manually by the maintainers.

Consider adding Dependabot to the repo. It will monitor and open issues when dependencies need updates
https://docs.github.com/en/code-security/tutorials/secure-your-dependencies/dependabot-quickstart-guide

Before adding dependabot, i would recommend adding additional quality checks to the git workflow. Currently only astro check is run
https://docs.astro.build/en/reference/cli-reference/#astro-check