fix: use architecture-aware ldid binary for ARM64 CI runners

[AztecBot]

Summary

• Fix canary CI failure on ARM64 (Graviton r7g) instances where ldid_linux_x86_64 cannot execute
• Changed all ldid installation paths to use ldid_linux_$(uname -m) to download the correct binary for the host architecture (x86_64 or aarch64)
• Made ldid -S failure non-fatal in inject_version (matching the existing codesign || true pattern for macOS)

Root Cause

Release CI ran on r7g.16xlarge (ARM64 Graviton) but ldid was hardcoded to ldid_linux_x86_64 in all installation paths, causing "Exec format error" during macOS cross-compilation signing.

Details

• CI log: http://ci.aztec-labs.com/1774559390465437
• Analysis: https://gist.github.com/AztecBot/3507bf51f3e510dc0e53cd2ff78e326c

Test plan

• CI release build passes on ARM64 Graviton instances
• macOS cross-compiled binaries are properly signed with ldid when available

[AztecBot]

Flakey Tests

🤖 says: This CI run detected 1 tests that failed, but were tolerated due to a .test_patterns.yml entry.

\033FLAKED\033 (8;;http://ci.aztec-labs.com/8dd3c4f80475c32c�8dd3c4f80475c32c8;;�):  yarn-project/end-to-end/scripts/run_test.sh simple src/e2e_epochs/epochs_mbps.pipeline.parallel.test.ts "pipelining builds blocks using slot plus 1 proposer and proves them" (270s) (code: 0) group:e2e-p2p-epoch-flakes