chore: bump git2-rs version to 0.17.2 and required libgit2 to v1.6.4

[kayagokalp]

Description

Bumps git2-rs to 0.17.2, so that forc requires libgit2 v1.6.4 to compile. This is needed as fuel.nix flake is in a deadlock; sysinfo dependency introduced in #4564 requires us to bump macos sdk versions while libgit2 v0.1.5.1 fails to compile with the bumped SDK version.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.