Re-enable forge doc in CI

[nategraf]

In CI, forge doc is intermittently failing with the following error. Since we don't actually use forge doc output anywhere yet and this is causing friction to land changes, this is disabled in #354. We should re-enable it when we have a chance to troubleshoot the issue.

 Error: Compiler run failed:
Error (9582): Member "VerifiedRoot" not found or not visible after argument-dependent lookup in type(contract IRiscZeroSetVerifier).
  --> contracts/test/RiscZeroSetVerifier.t.sol:45:14:
   |
45 |         emit IRiscZeroSetVerifier.VerifiedRoot(root);
   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[linear]

WEB3-255 Re-enable `forge doc` in CI