bump libgit2 (#10561)

Although this probably doesn't fix anything by itself, it'll make it
easier to fix https://github.com/libgit2/libgit2/issues/6795

Release Notes:

- N/A

Cargo.lock

@@ -4331,11 +4331,11 @@ dependencies = [
 
 [[package]]
 name = "git2"
-version = "0.15.0"
+version = "0.18.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2994bee4a3a6a51eb90c218523be382fd7ea09b16380b9312e9dbe955ff7c7d1"
+checksum = "232e6a7bfe35766bf715e55a88b39a700596c0ccfd88cd3680b4cdb40d66ef70"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.4.2",
  "libc",
  "libgit2-sys",
  "log",
@@ -5563,9 +5563,9 @@ checksum = "9c198f91728a82281a64e1f4f9eeb25d82cb32a5de251c6bd1b5154d63a8e7bd"
 
 [[package]]
 name = "libgit2-sys"
-version = "0.14.2+1.5.1"
+version = "0.16.2+1.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f3d95f6b51075fe9810a7ae22c7095f12b98005ab364d8544797a825ce946a4"
+checksum = "ee4126d8b4ee5c9d9ea891dd875cfdc1e9d0950437179104b183d7d8a74d24e8"
 dependencies = [
  "cc",
  "libc",

Cargo.toml

@@ -257,7 +257,7 @@ env_logger = "0.9"
 futures = "0.3"
 futures-batch = "0.6.1"
 futures-lite = "1.13"
-git2 = { version = "0.15", default-features = false }
+git2 = { version = "0.18", default-features = false }
 globset = "0.4"
 heed = { git = "https://github.com/meilisearch/heed", rev = "036ac23f73a021894974b9adc815bc95b3e0482a", features = ["read-txn-no-tls"] }
 hex = "0.4.3"