Bump circom_tester dependency to avoid vulnerable snarkjs version

[mcalancea]

circomkit installs circom_tester@0.0.19. In turn, this installs an old version of snarkjs which suffers from GHSA-xp5g-jhg3-3rg2. Consequently, circomkit introduces a critical vulnerability in npm audit reports.

I think that the vulnerability doesn't affect circomkit directly (it would be nice to confirm that), but updating circom_tester seems to not break anything and cleans up the package audit.

[erhant]

Nice catch, thank you! Indeed the vuln seems to be about field calculations which is beyond Circomkit, to confirm.