Docker images still inherit from Go 1.13 causing build issues

[proton-ab]

Thank you for creating the issue!

• Yes, I'm using a binary release within 2 latest major releases. Only such installations are supported.
• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've included all information below (version, config, etc).

Please include the following information:

Version of golangci-lint

$ golangci-lint --version
# 1.23.7

Config file

$ cat .golangci.yml
# - not relevant -

Go environment

$ go version && go env
# - not relevant -

Verbose output of running

$ golangci-lint run -v
# - not relevant -

While binaries itself are now built against Go 1.14, the Dockerfile still inherits from Go 1.13 images making it impossible to utilize docker images in CI to analyze code that depends on new Go 1.14 functions (such as t.Cleanup)