RPM build fix (reverted CI changes which will need to be un-reverted or made conditional) and vendor Rust dependencies to make builds much faster in any CI system.

zeroidc/vendor/encoding_rs/build.rs

@@ -0,0 +1,12 @@
+fn main() {
+    // This does not enable `RUSTC_BOOTSTRAP=1` for `packed_simd`.
+    // You still need to knowingly have a setup that makes
+    // `packed_simd` compile. Therefore, having this file on
+    // crates.io is harmless in terms of users of `encoding_rs`
+    // accidentally depending on nightly features. Having this
+    // here means that if you knowingly want this, you only
+    // need to maintain a fork of `packed_simd` without _also_
+    // having to maintain a fork of `encoding_rs`.
+    #[cfg(feature = "simd-accel")]
+    println!("cargo:rustc-env=RUSTC_BOOTSTRAP=1");
+}