Decouple kubesec analyzer from kubsec docker images

Release notes

Problem to solve

Our kubesec analyzer utilizes Docker containers published by kubesec as its base image. However, this bit of automation stopped working as of their latest release. This setup is blocking us from updating the analyzer to utilize the OSS project's latest version.

This can be observed by checking the release date of v2.8.0 and commit hash against the tags available in their docker hub. The most recent image published is one day older than when this version was published on GitHub.

Proposal

Refactor the kubesec analyzer so its base analyzer no longer relies upon the official kubesec images.