Update dependencies & minumum CI

[olegbespalov]

What?

• Update the k6 to the latest version, v0.49.
• Introduce the minimum CI

Why?

Currently, it's not building:

2024/02/09 15:07:59 [INFO] exec (timeout=0s): /home/olegbespalov/go/bin/go mod tidy -compat=1.17
go: downloading go.buf.build/grpc/go/prometheus/prometheus v1.4.4
go: k6 imports
        go.k6.io/k6/cmd imports
        github.com/grafana/xk6-output-prometheus-remote/pkg/remotewrite imports
        go.buf.build/grpc/go/prometheus/prometheus: unrecognized import path "go.buf.build/grpc/go/prometheus/prometheus": https fetch: Get "https://go.buf.build/grpc/go/prometheus/prometheus?go-get=1": dial tcp: lookup go.buf.build on 127.0.0.53:53: no such host

We need a CI for triggering CLA.