chore(build): Satiate clippy and its new lints

Cargo.toml

@@ -98,6 +98,9 @@ strum_macros = "0.26"
 assert_cmd = "2.0"
 predicates = "3.1"
 
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(build)'] }
+
 [package.metadata.git-cliff.git]
 protect_breaking_commits = true
 commit_parsers = [

build-aux/build.rs

@@ -17,6 +17,7 @@ include!("../src/cli.rs");
 
 fn main() {
     println!("cargo:rustc-cfg=build");
+    println!("cargo:rustc-check-cfg=cfg(build)");
     if let Ok(val) = env::var("AUTOTOOLS_DEPENDENCIES") {
         for dependency in val.split(' ') {
             println!("cargo:rerun-if-changed={dependency}");