[release-branch.go1.21] html/template: escape additional tokens in MarshalJSON errors
Escape "</script" and "<!--" in errors returned from MarshalJSON errors
when attempting to marshal types in script blocks. This prevents any
user controlled content from prematurely terminating the script block.
Updates #65697
Fixes #65968
Change-Id: Icf0e26c54ea7d9c1deed0bff11b6506c99ddef1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/564196
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
(cherry picked from commit
ccbc725f2d678255df1bd326fa511a492aa3a0aa)
Reviewed-on: https://go-review.googlesource.com/c/go/+/567515
Reviewed-by: Carlos Amedee <carlos@golang.org>