Track Optuna version

[halentin]

For example with dependabot in order to not miss new releases

[JulianTrommer]

The official documentation says that conda is not supported:
https://docs.github.com/en/code-security/reference/supply-chain-security/dependabot-options-reference#package-ecosystem-

However it was apparently added in this PR:
dependabot/dependabot-core#12767

[halentin]

Dependabot-Conda looks for a environment.yml, which has a different format to CondaPkg.toml. CondaPkg.toml is modelled somewhat after Julias Project.toml, so you would probably add this to Dependabot-Julia : https://github.com/dependabot/dependabot-core/tree/main/julia