flatpak-builder doesn't respect .gitignore when creating its local build
directory, so we need to explicitly skip potentially large ignored
directories to avoid bloating the flatpak build directory during builds.
We now clean up installed helper tools, includes from dependencies, and
pkgconfig/CMake files. This decreases the size of the flatpak from
~206MiB to ~150 MiB on my machine.
The manifest is also mostly clean of linter warnings from the
flatpack-builder manifest linter, with the exception of the overly broad
session bus policy.
The docs at https://docs.flathub.org/docs/for-app-authors/linter list a
method for selecting the correct session bus policies, but it is unclear
how to actually get the full set.
This build depends on the KDE Flatpak SDK, and builds any missing
dependencies manually as source modules.
The flatpak can be built with the following command:
```sh
flatpak-builder --user --force-clean --install-deps-from=flathub \
--ccache --repo=Build/repo --install Build/flatpak \
Meta/CMake/flatpak/org.ladybird.Ladybird.json
```
After building, the flatpak can be run with:
```sh
flatpak run --user --devel org.ladybird.Ladybird
```
If there are issues launching RequestServer, the .pid and .sock files
under $XDG_RUNTIME_DIR may need removed.
```sh
flatpak run --user --command=sh --devel org.ladybird.Ladybird
rm -f $XDG_RUNTIME_DIR/Ladybird.*
```
