[FEATURE]: Add R buildpack

### Description

for accademics and R users, that buildpack can increase the use cases of Kubero

### Possible solution

https://elements.heroku.com/buildpacks/virtualstaticvoid/heroku-buildpack-r

### Alternatives

_No response_

### Additional information

_No response_

Start by reviewing the proposed R buildpack at https://elements.heroku.com/buildpacks/virtualstaticvoid/heroku-buildpack-r and determine how Kubero currently supports buildpacks. Define what integration and validation are needed for academic and R users; done should mean Kubero can build and run an R application through the supported buildpack flow.

Written by the indexing model from the issue text.