Update to go 1.18.6 to address CVE-2022-27664, CVE-2022-32190

[thaJeztah]

From the mailing list:

We have just released Go versions 1.19.1 and 1.18.6, minor point releases.
These minor releases include 2 security fixes following the security policy:

• net/http: handle server errors after sending GOAWAY
  A closing HTTP/2 server connection could hang forever waiting for a clean
  shutdown that was preempted by a subsequent fatal error. This failure mode
  could be exploited to cause a denial of service.

  Thanks to Bahruz Jabiyev, Tommaso Innocenti, Anthony Gavazzi, Steven Sprecher,
  and Kaan Onarlioglu for reporting this.

  This is CVE-2022-27664 and Go issue https://go.dev/issue/54658.

• net/url: JoinPath does not strip relative path components in all circumstances
  JoinPath and URL.JoinPath would not remove ../ path components appended to a
  relative path. For example, JoinPath("https://go.dev", "../go") returned the
  URL https://go.dev/../go, despite the JoinPath documentation stating that
  ../ path elements are cleaned from the result.

  Thanks to q0jt for reporting this issue.

  This is CVE-2022-32190 and Go issue https://go.dev/issue/54385.

Release notes:

go1.18.6 (released 2022-09-06) includes security fixes to the net/http package,
as well as bug fixes to the compiler, the go command, the pprof command, the
runtime, and the crypto/tls, encoding/xml, and net packages. See the Go 1.18.6
milestone on the issue tracker for details;

https://github.com/golang/go/issues?q=milestone%3AGo1.18.6+label%3ACherryPickApproved

- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)