Remove references to TestGrandpaTestSuite

[DimitrisJim]

This e2e suite was removed at some point during sdk 0.52 upgrade. It is still referenced in our workflows (and is one causing one of em to consistently fail).

Should be possible to remove references to it.

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[gjermundgaraba]

We have #6835, as well, but we are def at place where we can just remove it entirely.

[DimitrisJim]

yea, I think for time being this is really just a clean-up of workflow files.