bump: Golang to v1.21 and remove Harvester dependency

[Yu-Jack]

Problem

When I run go list -m -mod=mod all, it shows following errors.

go: github.com/honestbee/jobq@v1.0.2: invalid version: git ls-remote -q origin in /Users/{user}/.gvm/pkgsets/go1.20/global/pkg/mod/cache/vcs/b7039093cfd5e54747139d9a392f45ffb733fb74488bd673022aa3b33e2ae79f: exit status 128:
        ERROR: Repository not found.
        fatal: Could not read from remote repository.
        
        Please make sure you have the correct access rights
        and the repository exists.
go: k8s.io/dynamic-resource-allocation@v0.0.0: invalid version: unknown revision v0.0.0

After checking some dependency of Harvester, we only used v1beta1.ErrorResponse (path is pkg/utils/http.go). So, I think we don't need to rely on it, just create own struct to remove dependency. Then Golang should be bumped to v1.21 due to EOL.

Test

• I tested collecting support bundle file and running simulator, both are fine.

[ibrokethecloud]

lgtm. thanks.