Conda builds (pyg-team#7018)

Increase PyG to version `2.2.0` (pyg-team#6105)

Remove `MutableMapping` base class in `FeatureStore` (pyg-team#5210)

* update

* changelog

* linting

* add a todo

* typo

[ci skip]

Remove size parameter for GATv2 and HEAT (pyg-team#3744)

* refactor heat_conv and test

* refactor gatv2_conv and test

fix coalesce on CUDA

version up

update conda installation

[ci skip]

typo