Remove duplicate instances of `-Z build-std`

{{project-name}}-ebpf/.cargo/config.toml

@@ -1,7 +1,3 @@
-# We have this so that one doesn't need to manually pass
-# --target=bpfel-unknown-none -Z build-std=core when running cargo
-# check/build/doc etc.
-#
 # NB: this file gets loaded only if you run cargo from this directory, it's
 # ignored if you run from the workspace root. See
 # https://doc.rust-lang.org/cargo/reference/config.html#hierarchical-structure

{{project-name}}/build.rs

@@ -60,8 +60,6 @@ fn main() {
         let mut cmd = Command::new("cargo");
         cmd.args([
             "build",
-            "-Z",
-            "build-std=core",
             "--bins",
             "--message-format=json",
             "--release",