fix: mark all signed binary ops as unchecked

[TomAFrench]

Description

Problem*

Resolves #9047

Summary*

Shows a fix for #9047. I think that we probably want to go a bit further and push the overflow checks for the signed operations inside of the actual binary instruction. This can then have an SSA pass which expands these into the current format but we should avoid the jankiness which currently exists around signed types.

Additional Context

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Changes to Brillig bytecode sizes

Generated at commit: 8e52c9c8271fe2795e9fae47376dcb48e229a27d, compared to commit: d6920017a3b1ae0a1c927e50b01ca748d901e9ce

🧾 Summary (10% most significant diffs)

Program	Brillig opcodes (+/-)	%
higher_order_functions_inliner_zero	-1 ✅	-0.15%

---

Full diff report 👇

Program	Brillig opcodes (+/-)	%
higher_order_functions_inliner_zero	651 (-1)	-0.15%

[github-actions]

Changes to number of Brillig opcodes executed

Generated at commit: 8e52c9c8271fe2795e9fae47376dcb48e229a27d, compared to commit: d6920017a3b1ae0a1c927e50b01ca748d901e9ce

🧾 Summary (10% most significant diffs)

Program	Brillig opcodes (+/-)	%
higher_order_functions_inliner_zero	+6 ❌	+0.51%

---

Full diff report 👇

Program	Brillig opcodes (+/-)	%
higher_order_functions_inliner_zero	1,192 (+6)	+0.51%

[TomAFrench]

hmm, interesting. I didn't expect this to affect brillig outputs for existing programs 🤔

[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Test Suite Duration'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: 030669b	Previous: 3838c69	Ratio
test_report_AztecProtocol_aztec-packages_noir-projects_aztec-nr	101 s	75 s	1.35
test_report_AztecProtocol_aztec-packages_noir-projects_noir-contracts	153 s	127 s	1.20
test_report_AztecProtocol_aztec-packages_noir-projects_noir-protocol-circuits_crates_blob	173 s	141 s	1.23
test_report_AztecProtocol_aztec-packages_noir-projects_noir-protocol-circuits_crates_types	95 s	73 s	1.30

This comment was automatically generated by workflow using github-action-benchmark.

CC: @TomAFrench