The `HOME` path is not persistent when using the rootless image, so the
`.gnupg` folder isn't either. Since the chart always used `/data/...` as
mount point for storage of all kinds, it is a minimal impact to just
relocate the dynamic `$HOME/.gnupg` folder location to the persistent
`/data/git/.gnupg`. This is where the signing keys are stored when
running root based environments. Doing so will
- allow migrations between both image variants
- persist signing keys for rootless environments
Fixes: #155