Updating mergo to 0.3.11

mergo had made a breaking change in 0.3.9. This was undone in 0.3.10
with a new path forward for internal reworking via a new implementation.
0.3.10 and 0.3.11 no longer break sprig functionality. This is tested.
More information at https://github.com/imdario/mergo/releases/tag/v0.3.10