Tracking issue for some remaining linting issues to be fixed after #39668 is merged.

integration-cli/docker_api_attach_test.go:239:134:    SA1019: httputil.ClientConn is deprecated: Use Client or Transport in package net/http instead.  (staticcheck)

These warnings are currently suppressed in hack/validate/golangci-lint.yml (after #39668 is merged), so when this is fixed, those lines should be removed