Tidy up environment.yml file

[pont-us]

For package build configurations, dependency version specifications must follow conda's package match specification syntax, which differs from the version specification syntax used by conda's command-line tool. Strangely, the version syntax used in environment.yml files doesn't seem to be documented anywhere; however, there is an example environment file in the conda documentation which uses something that looks like the command-line syntax. Nevertheless, we have so far mostly using the package match specification syntax in xcube's environment.yml, so it's evidently supported by both conda and mamba. Since the package list in environment.yml must be kept in sync with the list in meta.yaml in the conda-forge feedstock, it seems sensible to standardize completely on package match specification syntax in environment.yml to make this process slightly more straightforward. In order to further ease the synchronization (and make management of the dependency list easier in general), packages should be listed alphabetically within each section (already mostly the case in our environment file).

[pont-us]

Closed by PR #342 .