I've been investigating more into how ostree works and how it relates to
running `ostree container commit` for each layer. I've decided to move
our pre-installed bins and public keys into their own stages and then
bind mount them into a `RUN` instruction so that we can just use `cp` to
get the files into the image and then call `ostree container commit`.
Now all of our layers in the image (after the base image) will be in the
ostree commit tree.
https://github.com/blue-build/cli/issues/118#issuecomment-1992536977
as mentioned here reverting to the bash files module simplifies the
build process (and allows for better usage of `ostree container
commit`). It also means there are less overall layers and (ideally) a
smaller image as a result. Tested locally and template generation seems
to work just fine
Since the command `ostree container commit` checks for the presence of
mounted directories, we will be running it at the end of each module
run. We have also updated the final commit to remove from /tmp/ and
/var/ again in case a user creates extra files through custom
instructions.
Closes#101#95
