build: bump git2 from 0.17.2 to 0.18.3

Author: jirutka

Cargo.lock

@@ -69,7 +69,7 @@ git-branchless-smartlog = { version = "0.8.0", path = "git-branchless-smartlog"
 git-branchless-submit = { version = "0.8.0", path = "git-branchless-submit" }
 git-branchless-test = { version = "0.8.0", path = "git-branchless-test" }
 git-branchless-undo = { version = "0.8.0", path = "git-branchless-undo" }
-git2 = { version = "0.17.2", default-features = false }
+git2 = { version = "0.18.3", default-features = false }
 glob = "0.3.0"
 indexmap = "2.2.6"
 indicatif = { version = "0.17.8", features = ["improved_unicode"] }