Update libbpf-rs & libbpf-cargo to 0.23.1

Summary:
Update the libbpf-rs and libbpf-cargo crates to version 0.23.1 to get the
latest and greatest.

Reviewed By: anakryiko

Differential Revision: D57113437

fbshipit-source-id: 50597e92ad645abfa64b2fe16e491bdb6e2a6b17

below/Cargo.toml

@@ -29,7 +29,7 @@ config = { package = "below-config", version = "0.8.1", path = "config" }
 cursive = { version = "0.20.0", features = ["crossterm-backend"], default-features = false }
 dump = { package = "below-dump", version = "0.8.1", path = "dump" }
 indicatif = { version = "0.17.6", features = ["improved_unicode", "rayon", "tokio"] }
-libbpf-rs = { version = "0.23", default-features = false }
+libbpf-rs = { version = "0.23.1", default-features = false }
 libc = "0.2.139"
 model = { package = "below-model", version = "0.8.1", path = "model" }
 once_cell = "1.12"
@@ -52,7 +52,7 @@ maplit = "1.0"
 portpicker = "0.1.1"
 
 [build-dependencies]
-libbpf-cargo = { version = "0.23", default-features = false }
+libbpf-cargo = { version = "0.23.1", default-features = false }
 
 [features]
 default = ["libbpf-cargo/default", "libbpf-rs/default"]