Build: unpin version of base image of dockered development environment
This PR removes the pinned version for the base image.

The latest version of the base image, `quay.io/condaforge/miniforge3:4.11.0-4` (released Feb 26, 2022),  works again.

The pinned version was needed temporarily because of a misbehaving version of the base image: https://github.com/pandas-dev/pandas/pull/45889#issuecomment-1040827073
thanks @rendner 