Bump git2 from 0.19.0 to 0.20.4

Bumps [git2](https://github.com/rust-lang/git2-rs) from 0.19.0 to 0.20.4.
- [Changelog](https://github.com/rust-lang/git2-rs/blob/git2-0.20.4/CHANGELOG.md)
- [Commits](rust-lang/git2-rs@git2-0.19.0...git2-0.20.4)

---
updated-dependencies:
- dependency-name: git2
  dependency-version: 0.20.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.lock

@@ -28,7 +28,7 @@ codegen-units = 256
 anyhow = "1"
 base64 = "0.21.2"
 dashmap = "6.1.0"
-git2 = "0.19.0"
+git2 = "0.20.4"
 indexmap = { version = "2.11", features = ["serde"] }
 itertools = "0.14.0"
 derive_builder = "0.12"