fix update releases workflow

[JoshuaBatty]

Summary

This fixes the update-releases workflow path that failed after the forc-wallet v0.16.4 release and backfills the missing releases.toml entry that the failed automation never landed.

Root cause

The failing run was the Update releases.toml job in CI run 24651220002.

actions/checkout@v6 persisted an auth header in the release-tag checkout, and peter-evans/create-pull-request added another one when it prepared the PR branch. During git remote prune origin, GitHub rejected the request with 400 Duplicate header: "Authorization", so the final PR-creation step failed even though the release metadata update itself succeeded.

Changes

• set persist-credentials: false on the Checkout release tag step in .github/workflows/ci.yml
• upgrade peter-evans/create-pull-request from v6 to v8
• add the missing forc-wallet 0.16.4 entry to releases.toml

Impact

Future release runs should be able to create the follow-up releases.toml PR without tripping over duplicate GitHub auth headers, and main regains the missing compatibility metadata for forc-wallet 0.16.4.

Validation

• git diff --check origin/main...HEAD
• verified the failing GitHub Actions log for run 24651220002 and matched the workflow fix to the observed Duplicate header: "Authorization" error

[cursor]

PR Summary

Medium Risk
Medium risk because it changes release-time GitHub Actions behavior (credentials handling and PR creation action version), which could affect automated post-release PR generation.

Overview
Fixes the release update-releases workflow so it can reliably open the follow-up PR to releases.toml after a tag is published by disabling credential persistence on the tag checkout and upgrading peter-evans/create-pull-request to v8.

Backfills the missing releases.toml entry for forc-wallet 0.16.4 (including its recorded fuels-rs version).

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