update go to go1.20.6

go1.20.6 (released 2023-07-11) includes a security fix to the net/http package,
as well as bug fixes to the compiler, cgo, the cover tool, the go command,
the runtime, and the crypto/ecdsa, go/build, go/printer, net/mail, and text/template
packages. See the Go 1.20.6 milestone on our issue tracker for details.

https://github.com/golang/go/issues?q=milestone%3AGo1.20.6+label%3ACherryPickApproved

Full diff: https://github.com/golang/go/compare/go1.20.5...go1.20.6

These minor releases include 1 security fixes following the security policy:

net/http: insufficient sanitization of Host header

The HTTP/1 client did not fully validate the contents of the Host header.
A maliciously crafted Host header could inject additional headers or entire
requests. The HTTP/1 client now refuses to send requests containing an
invalid Request.Host or Request.URL.Host value.

Thanks to Bartek Nowotarski for reporting this issue.

Includes security fixes for [CVE-2023-29406 ][1] and Go issue https://go.dev/issue/60374

[1]: https://github.com/advisories/GHSA-f8f7-69v5-w4vx

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Dockerfile

@@ -15,7 +15,7 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-ARG GO_VERSION=1.20.5
+ARG GO_VERSION=1.20.6
 ARG XX_VERSION=1.2.1
 ARG GOLANGCI_LINT_VERSION=v1.53.2
 ARG ADDLICENSE_VERSION=v1.0.0