Set rust_target to 1.68 for bindgen output

Author: ldm0

build.rs

@@ -1,3 +1,4 @@
+use bindgen::RustTarget;
 use bindgen::{callbacks, Bindings};
 use camino::Utf8Path as Path;
 use camino::Utf8PathBuf as PathBuf;
@@ -226,6 +227,7 @@ fn generate_bindings(ffmpeg_include_dir: &Path, headers: &[PathBuf]) -> Bindings
                 bindgen::builder()
                     // Force impl Debug if possible(for `AVCodecParameters`)
                     .impl_debug(true)
+                    .rust_target(RustTarget::Stable_1_68)
                     .parse_callbacks(Box::new(filter_callback))
                     // Add clang path, for `#include` header finding in bindgen process.
                     .clang_arg(format!("-I{}", ffmpeg_include_dir))