Migrate golangcilint

[datosh]

Migrated golangci-lint to version 2 as we were already using version 2.x of golangci-lint, to fix pipeline in #122

I migrated the configuration file using the tool assissted approach as per documentation. This leads to some changes, most relevant for us "run.timeout: the existing value is ignored because, in v2, there is no timeout by default.". I would say we accept this for now, and if the action takes too long we add a timeout there.

There have also been changes to the used linters (even though I followed their docs). gosimple for example was available in v1 but vanished in v2.

Do you have strong feelings about the included linters @EthanHeilman ?
Happy to add more in this PR or create an issue to look into this.

[EthanHeilman]

No strong feelings about which linters to use as long as they cover roughly the same cases.

Below I just did a double check what is default now and it seems like we only lost gosimple. However I don't think that is a big loss as gosimple has been depreciated in favor of staticcheck.

previously we had:

 gosimple
 govet
 ineffassign
 staticcheck
 unused
 misspell
 gofmt

now:

govet - enabled by default
ineffassign - enabled by default
staticcheck - enabled by default
unused - enabled by default
errcheck -  enabled by default
misspell
gofmt

[EthanHeilman]

LGTM