Update golang to 1.19

[thbkrkr]

I changed my mind about continuing to delay the update of go module to 1.18 (#5884) and golang to 1.19 (#5920). I would not like us to accumulate tech debt by pushing the update.

Here are the changes made by this PR:

• Update to docker.io/library/golang:1.19.0
• Update module go to 1.19
• Update golangci-lint to 1.48.0
• Remove ifshort linter deprecated since golangci-lint v1.48.0
• Protect from Potential Slowloris Attack by setting ReadHeaderTimeout
• Refactor comments after running go fmt (1.19)

Two linters are disabled until generics are fully supported. I think it's acceptable.

WARN [linters context] structcheck is disabled because of generics. You can track the evolution of the generics support by following the https://github.com/golangci/golangci-lint/issues/2649. 
WARN [linters context] wastedassign is disabled because of generics. You can track the evolution of the generics support by following the https://github.com/golangci/golangci-lint/issues/2649. 

Replaces #5938 and #5919.

[thbkrkr]

Build PR failure:

[2022-08-10T15:16:38.847Z] docker: Error response from daemon: Head "https://registry-1.docker.io/v2/garethr/kubeval/manifests/latest": Get "https://auth.docker.io/token?scope=repository%3Agarethr%2Fkubeval%3Apull&service=registry.docker.io": EOF.

Jenkins test this please again.

[barkbay]

LGTM !
Thanks 🙇