Docker image does not match changes for MODE env variable

[bizrad]

The #7 introduced new test modes, but the docker image yasker/kbench:latest appears to not have been updated to contain the same changes from this MR.

Please update the docker image so that the new environment variables work.

Setting this does not enable quick mode with the current deployment yaml https://github.com/longhorn/kbench/blob/main/deploy/fio.yaml

        env:
        - name: MODE
          value: "quick" # for debugging

[bizrad]

Since the dockerhub image is 2 years old I just decided to fork and make my own build to get things working for me.

Here are the files if anyone else is interested:
Multi-stage Dockerfile
GitHub Docker build action

Docker image:
ghcr.io/bizrad/kbench:main@sha256:87e20d760f536a0dbdb46f1df50099cd920a0afa59aaa0b8089d3d73032bae93

[derekbit]

cc @PhanLe1010