intent-gizmosql: add the arm64 build (c8g machines)

[ZENGXH]

The release v1.38.0-clickbench.1 now also ships an arm64 build (gizmosql_cli_linux_arm64.zip, SHA256SUMS.arm64): the same source tag, built with the same manylinux recipe on an aarch64 machine, glibc 2.28 baseline. install selects the zip by uname -m (x86_64 → amd64, aarch64 → arm64) and verifies its SHA-256; the README mentions both builds. No other file changed.

This fixes the two runs of the previous PR that produced no results (Exec format error on c8g.4xlarge and c8g.metal-48xl). A fresh c8g.4xlarge run of this branch on our side completed all 43 queries (load 118 s).

Could you run it with machine:c8g.4xlarge and machine:c8g.metal-48xl (or machine:all)? Thanks.

[ZENGXH]

For reference, this branch also completed on c8g.metal-48xl on our side (43/43, load 98 s), so both c8g machine types should produce results now.

[github-actions]

Results for intent-gizmosql are ready for: c8g.4xlarge, c8g.metal-48xl.
This pull request is from a fork, so the automation cannot push to it; save this result as intent-gizmosql/results/20260920/c8g.metal-48xl.json.
This pull request is from a fork, so the automation cannot push to it; save this result as intent-gizmosql/results/20260920/c8g.4xlarge.json.

Logs:

• intent-gizmosql on c8g.metal-48xl: benchmark log, cloud-init log
• intent-gizmosql on c8g.4xlarge: benchmark log, cloud-init log

[ZENGXH]

Committed both collector results as intent-gizmosql/results/20260920/c8g.4xlarge.json and c8g.metal-48xl.json (43/43, no missing values on either machine). Thank you for the run.