Enable backends/cadence with mypy

[mergennachin]

Enable mypy and disable pyre altogether since pyre isn't available for OSS contributors.

Partially fixes #7441

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✅ You can merge normally! (1 Unrelated Failure)

As of commit d60cb49 with merge base be65301 ():

BROKEN TRUNK - The following job failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest-nxp-neutron / linux-job (gh) (trunk failure)
  test_split_group_convolution__applied_by_default

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