shells/elvish: Update to v0.19.2

ChangeLog: https://elv.sh/blog/0.19.1-release-notes.html

 * A new doc module provides access to the documentation of builtin modules.
 * A new conj command “appends” values to a list, and has a guaranteed time
   complexity independent of the size of the list.
 * A new inexact-num converts its argument to an inexact number.
 * It is functionally identical to the now deprecated float64 command since the
   Go float64 type is the only underlying inexact number type for now. Its
   behavior may change in future if there are more underlying types for inexact
   numbers.
 * A new type of interactive abbreviation: edit:command-abbr
 * The order and compare commands now support boolean values
 * A new path:join command and path:separator and path:list-separator variables
 * A new runtime: module that contains paths important for the Elvish runtime
 * A new compact command that replaces consecutive runs of equal values with a
   single copy, similar to the Unix uniq command.
 * The order command has a new &key option
 * A new benchmark command has been added
 * When checking compilation errors, Elvish no longer stops after the first
   error found. For example, if $a and $b are both not defined, echo $a $b now
   yields two errors. This applies to both the interactive REPL and elvish
   -compile-only.
 * When using an unimported builtin modules from the REPL, the REPL now shows
   the use command needed to import it, which can be executed from a key
   binding. This functionality is bound to Ctrl-A by default.
 * New variables exposing the terminal and null device in an OS-agnostic
   fashion: $path:dev-tty and $path:dev-null. They are /dev/tty and /dev/null on
   Unix, and CON and NUL on Windows

PR:		275422
Reported by:	vendion@gmail.com (maintainer)