Locally reproducible CI/CD

[kakkoyun]

We want vendor-independent and locally reproducible CI/CD pipelines so that our contributors can ensure quality before opening the pull requests.

xref: cncf/mentoring#1120

cc @ArthurSens

[dvjsharma]

Hi @kakkoyun, navigated here form the LFX portal. Since this is particularly about unit testing in specific environments, We can allow contributors to specify the Go version they want to use through environment variables and modify the CI/CD scripts to interpret these variables and set up the corresponding Go version for testing. We certainly will have to find a way to manage dependencies. Or how about using 3 different docker images for 3 test environments? What are your thoughts?