test: sync forge-std-rev to v1.16.2 to fix forge-std revision-mismatch warning

[stephancill]

Motivation

base-anvil-fork CI's test / test all job fails on three CLI tests:

• forge::cli build::build_no_warning_without_soldeer_lock
• forge::cli cmd::can_clean_without_warnings
• forge::cli test_cmd::repros::issue_9272

All three fail for the same reason — forge build emits a spurious warning:

Warning: Dependency 'lib/forge-std' revision mismatch:
  expected 'bf647bd6046f2f7da30d0c2bf435e5c76a780c1b',
  found    '620536fa5277db4e3fd46772d5cbc1ea0696fb43'

The first two assert zero warnings; issue_9272 asserts an exact stderr snapshot and the warning is prepended as an extra line.

Root cause

The shared test template (crates/test-utils/src/util.rs) runs forge init (which writes a foundry.lock pinning forge-std at bf647bd6, i.e. v1.16.2) and then force-checks-out FORGE_STD_REVISION (= testdata/forge-std-rev) into lib/forge-std. Our testdata/forge-std-rev was stale at 620536fa (Apr 2026), so the checked-out rev no longer matched the lock and check_foundry_lock_consistency warned.

Solution

Bump testdata/forge-std-rev 620536fa → bf647bd6, matching upstream foundry-rs/foundry's testdata/forge-std-rev (forge-std v1.16.2). Now the template checkout matches the lock forge writes, so no mismatch warning is emitted.

One-line change; format preserved (40-byte SHA, no trailing newline). Validated the target value against upstream foundry's pin; the test / test all job on this PR exercises the fix end-to-end.

Not addressed

test / test external (ext_integration::gunilev, convex_shutdown_simulation) fork Ethereum mainnet over a public RPC and are environmental flakes, unrelated to this change.

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[stephancill]

Folding this into the CI maintenance PR #51 instead.