go120: update to 1.20.4 (security)

This minor release includes 3 security fixes following the security policy:

* html/template: improper sanitization of CSS values

  Angle brackets (<>) were not considered dangerous characters when inserted
  into CSS contexts. Templates containing multiple actions separated by a '/'
  character could result in unexpectedly closing the CSS context and allowing
  for injection of unexpected HMTL, if executed with untrusted input.

  Thanks to Juho Nurminen of Mattermost for reporting this issue.

  This is CVE-2023-24539 and Go issue https://go.dev/issue/59720.

* html/template: improper handling of JavaScript whitespace

  Not all valid JavaScript whitespace characters were considered to be
  whitespace. Templates containing whitespace characters outside of the
  character set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also
  contain actions may not be properly sanitized during execution.

  Thanks to Juho Nurminen of Mattermost for reporting this issue.

  This is CVE-2023-24540 and Go issue https://go.dev/issue/59721.

* html/template: improper handling of empty HTML attributes

  Templates containing actions in unquoted HTML attributes (e.g. "attr={{.}}")
  executed with empty input could result in output that would have unexpected
  results when parsed due to HTML normalization rules. This may allow injection
  of arbitrary attributes into tags.

  Thanks to Juho Nurminen of Mattermost for reporting this issue.

  This is CVE-2023-29400 and Go issue https://go.dev/issue/59722.


(bsiegert)