Import error on `from collections import Mapping` when running on Python 3.10

[mz8i]

When installing from source using conda env create -f environment.yml, I get Python 3.10 installed due to the dependency specifier python>=3.6.

However, running the server and querying /singleband results in errors with message AttributeError: module 'collections' has no attribute 'MutableMapping'

Probably related: https://stackoverflow.com/questions/70195545/module-collections-has-no-attribute-mapping-issue-on-macos-for-sdk-installa

Manually editing environment.yml to specify python==3.9 fixed the problem for me.

Suggestion: move from from collections import Mapping to from collections.abc import Mapping, or mark Python 3.10 as not supported yet

[dionhaefner]

There's still no rasterio wheel for Python 3.10, so support is somewhat experimental. I'll have a look at how things stand with conda. But since we don't use MutableMapping this is likely a dependency issue.

[dionhaefner]

Fixed the Mapping issue, so running on 3.10 via conda should work fine now.