shells/yash update to 2.54.

# CHANGES

Yash 2.54 (2023-02-25)

  +  Changing font style of command line predictions with $PS1P, etc.
  +  The '--le-trim-right' option.
  =  When the POSIXly-correct mode is active, the shell now refuses to
    execute built-ins POSIX XCU 2.9.1 lists as utilities that cause
    unspecified results. To implement the new behavior, the previous
    "semi-special" built-ins are now categorized in either of the new
    categories "mandatory" and "elective". The "command" and "type"
    built-ins now report the new categories of such built-ins.
  =  The shell now requires a corresponding external executable to
    exist in $PATH when running a built-in that works like a standard
    external utility even when the POSIXly-correct mode is inactive.
    Such built-ins are now categorized as "substitutive" built-ins.
  =  The "array" built-in is now completely ignored in the POSIXly-
    correct mode. The built-in, formerly a regular built-in, is now
    categorized as an "extension" built-in.
  =  The xtrace option is now ignored while expanding the $PS4
    variable to prevent possible infinite recursion.
  *  The allexport option was wrongly ignored in many assignment
    contexts.
  *  The errexit and errreturn options now work for assignment error
    in a for loop.
  *  The ">" redirection with the noclobber option no longer hangs
    when the operand names a symbolic link to a non-existing file.
  *  The exported value of the $DIRSTACK variable was not being
    updated correctly in the "pushd" and "popd" built-ins.
  *  The effect of "!" no longer applies to the exit status of the
    "break", "continue", and "return" built-ins.
  *  An alias value ending with a blank followed by a line
    continuation no longer subjects the next token to alias
    substitution.
  .  Updated the sample initialization script (yashrc):
    +  The "o" alias for WSL

(vins)