Remove deprecated LightningDistributed

[akihironitta]

What does this PR do?

Part of #12521.
Closes #13492

resolves #9691

Does your PR introduce any breaking changes? If yes, please list them.

Removes pl.distributed.LightningDistributed

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Did you have fun?

Make sure you had fun coding 🙃

cc @awaelchli @rohitgr7 @akihironitta @Borda

[otaj]

Can you please also remove the file from typing checks in this PR if it passes now in pyproject.toml? Thanks!