chore: makes ec addition opcode unsafe

[guipublic]

This PR is the same as #8374, but with some added runtime checks as suggested by @zac-williamson.
#8374 was merged and then rollback because it caused issues with e2e tests.
We should not merge this one until this issue is fixed, but I need the PR as ready for review in order to have the CI to run.

The PR makes the ACIR opcode 'EC ADD' unsafe because the safety checks are now done on the Noir side in the stdlib's embedded curve operations.
It will allow Aztec protocol circuit to use directly the opcode when the 'safety' is already known (and implied by previous operations).

[github-actions]

Changes to circuit sizes

Generated at commit: 393fe779227f5114dd6044e3b1c5dda768b6f719, compared to commit: 1801f5b49fb3b153817a1596c6fd568f1c762fe5

🧾 Summary (100% most significant diffs)

Program	ACIR opcodes (+/-)	%	Circuit size (+/-)	%
private_kernel_reset_4_4_4_4_4_4_4_4_1	0 ➖	0.00%	-4 ✅	-0.01%
private_kernel_reset	0 ➖	0.00%	-64 ✅	-0.01%

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Full diff report 👇

Program	ACIR opcodes (+/-)	%	Circuit size (+/-)	%
private_kernel_reset_4_4_4_4_4_4_4_4_1	34,897 (0)	0.00%	74,475 (-4)	-0.01%
private_kernel_reset	91,933 (0)	0.00%	467,666 (-64)	-0.01%

[TomAFrench]

Happy to merge once CI is passing.