command substitution when timing grouped commands fails

[hackerb9]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -g -O2 -fstack-protector-strong -Wformat 
-Werror=format-security -Wall
uname output: Linux abyssal 6.4.0-3-amd64 #1 SMP PREEMPT_DYNAMIC Debian 
6.4.11-1 (2023-08-17) x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 5.2
Patch Level: 15
Release Status: release

Description:

        Bash gives a syntax error when using the $(...) form of
        command substitution and timing grouped commands.

        However, Bash works correctly when using the `...` form of
        command substitution.


Repeat-By:

        The 'time' built-in command can measure a group of commands
        run in a subshell, for example:

            $ time (date; sleep 1)
            Thu Sep  7 05:19:21 AM PDT 2023

            real    0m1.005s
            user    0m0.003s
            sys     0m0.001s

        Attempting to save the output of time to a variable fails when
        using $(...) command substitution. For example,

            $ x=$( time ( date; sleep 1 ) 2>&1 )
            -bash: syntax error near unexpected token `date'

        However, old versions of bash (~2016) used to work correctly.
        And, indeed, even the current version of bash works if one
        uses backticks for command substitution.

            $ x=` time ( date; sleep 1 ) 2>&1 `
            $                                           # no error

        There should be no difference between $(...) and `...`.