Do not copy developer versions of libzim binaries into final release packages

[Jaifroid]

The packaging scripts copy all the code under www into final release packages. Unfortunately, developer version of the libzim binaries, which are necessary to work with, therefore got included in version 3.7.0. One of these in particular, the JS ASM version, is very large due to all the comments in the unminified version. This increased the app size by a factor of 10, unnecessarily, since the file will never be read by the app.

The Firefox store complained about this, so I removed the offending files. I did the same for the Edge Store submission.

The packaging app needs to exclude explicitly any files marked as dev, before the next release is prepared.