build-rust-crate: disable incremental builds

According to rustc implementation[1], `-C incremental=no` enables
incremental builds with directory name `no`. This patch removes the
`-C incremental` argument to disable incremental builds.

[1]: https://github.com/rust-lang/rust/blob/ee86f96ba176f598d64dc9f3bb7e074d5b8b86b6/compiler/rustc_session/src/options.rs#L918-L919

pkgs/build-support/rust/build-rust-crate/build-crate.nix

@@ -12,7 +12,6 @@
       [
         (if release then "-C opt-level=3" else "-C debuginfo=2")
         "-C codegen-units=$NIX_BUILD_CORES"
-        "-C incremental=no"
         "--remap-path-prefix=$NIX_BUILD_TOP=/"
         (mkRustcDepArgs dependencies crateRenames)
         (mkRustcFeatureArgs crateFeatures)

pkgs/build-support/rust/build-rust-crate/configure-crate.nix

@@ -24,7 +24,7 @@ let version_ = lib.splitString "-" crateVersion;
     version = lib.splitVersion (lib.head version_);
     rustcOpts = lib.foldl' (opts: opt: opts + " " + opt)
         (if release then "-C opt-level=3" else "-C debuginfo=2")
-        (["-C codegen-units=$NIX_BUILD_CORES -C incremental=no"] ++ extraRustcOpts);
+        (["-C codegen-units=$NIX_BUILD_CORES"] ++ extraRustcOpts);
     buildDeps = mkRustcDepArgs buildDependencies crateRenames;
     authors = lib.concatStringsSep ":" crateAuthors;
     optLevel = if release then 3 else 0;