fix: `bundle` includes ephemeral and ignored files

**Description**

Mason's `bundle` (therefore `publish` too) include files ignored by `.gitignore` in the file.
This can lead to a handful of situations where local files are shipped within a brick that the user didn't intend to.
For example: `very_good_flutter_plugin` included several files under `.dart_tool` and `.idea` after running `mason publish` locally. See [this diff](https://github.com/VeryGoodOpenSource/very_good_cli/commit/e10b59e585c7b6a2aa0c8d659be4c827d8deed20#diff-f9b9b3c1300473239cc8da75ca2fc7a407bba63f38c4bbaff25f462facc0e2feL106).

**Expected Behavior**

It is necessary to provide a what to ignore .gitignored files or provide a species of .masonignore file to be placed within