My pixel font editor (redux). It can export AngelCode BMFont files, or SVGs optionally accompanied with a script to generate a FontForge project.
You can find pre-compiled Windows and Linux packages on the releases page.
LibGDX, and (as far as I know) Godot use BMFont config format for bitmap fonts. MonoGame.Extended package adds BMFont support to MonoGame.
Load a project, and from the menu select "Export SVG" command (shortcut Ctrl + Shift + E). On the opened dialog, select a directory to save the exported files and press "Export". If you didn't uncheck the option, this will also create a file with .pe extension. Open the save directory in the terminal and run (assuming you have FontForge installed and on the path)
fontforge -script <file_name>.pe
Now you will see a new file with .sfd extension. You can open it using FontForge and export your font from there.
You'll need JDK 18+ and Maven. Then, open a terminal in the project root and run
mvn package
If everything went OK, you should see two zip files in the target folder: one that also contains a minimal Java runtime environment, other that doesn't.