Clock module format "%Ex" does not produce expected output in v0.10.0

[Yutsuten]

It broke in the latest release (v0.10.0).

This is the relevant configuration (inside clock: ):

{
    "format": "{:L%Ex (%a)  %H:%M}"
}

What waybar shows:

The expected output is like the output of this date command:

$ date '+%Ex (%a)  %H:%M'
令和06年03月22日 (金)  23:27

This is my locale:

$ localectl
System Locale: LANG=ja_JP.UTF-8
    VC Keymap: jp106
   X11 Layout: (unset)

[ordy]

Made the tests fail on ja_JP locale to make sure, and yeah it looks like the new implementation of fmt can't display the japanese era years anymore.

(top is current version, bottom 0.9.24)