Unable to call commands by name with `M-x` in SDL2 interface

[ryan-carpenter]

1. Update to lem 2.2.0-99a53db2
2. Run make sdl2-ncurses*
3. Run lem -i SDL2
4. Press M-x (Alt-x)
5. Keypress does not activate the interactive pop-up and no commands can be executed by name.

The popup works as expected in ncurses and worked previously in SDL2 using a version from several months ago. My config and init files are empty except for a font-size setting and (in-package :lem-user) and the current environment is shown here: https://github.com/lem-project/lem/issues/1561#issuecomment-2964805676.

Potentially related: https://github.com/lem-project/lem/issues/917

*After commenting out libncursesw.so.6 as described here: https://github.com/lem-project/lem/issues/330#issuecomment-2964449047