https://github.com/stac-utils/pgstac/blob/main/src/pypgstac/pyproject.toml

Such pinning makes it impossible to integrate this tool into other projects (without hacky workarounds like override-dependencies, forceful dependency overrides). And I assume the intention is to allow such use cases given the existence of py.typed file which otherwise would be redundant.

There exist online resources on this topic: https://discuss.python.org/t/should-i-be-pinning-my-dependencies/13159

A popular and good practice is to use >= for defining your dependencies.