Update for rust2rpm 20 and remove nix downgrade

alsa-fix-metadata.diff

@@ -1,11 +0,0 @@
---- alsa-0.6.0/Cargo.toml	1970-01-01T00:00:01+00:00
-+++ alsa-0.6.0/Cargo.toml	2021-11-03T23:18:25.317265+00:00
-@@ -33,7 +33,7 @@
- version = "0.2.105"
- 
- [dependencies.nix]
--version = "0.23"
-+version = "0.22"
- [badges.is-it-maintained-issue-resolution]
- repository = "diwic/alsa-rs"
- 

rust-alsa.spec

@@ -1,4 +1,4 @@
-# Generated by rust2rpm 18
+# Generated by rust2rpm 20
 # Deactivate tests because they need a sound card
 # https://github.com/diwic/alsa-rs/issues/71
 %bcond_with check
@@ -15,14 +15,8 @@ Summary:        Thin but safe wrappers for ALSA (Linux sound API)
 License:        ASL 2.0 or MIT
 URL:            https://crates.io/crates/alsa
 Source:         %{crates_source}
-# Initial patched metadata
-# Downgrade nix to version 0.22
-Patch0:         alsa-fix-metadata.diff
 
 ExclusiveArch:  %{rust_arches}
-%if %{__cargo_skip_build}
-BuildArch:      noarch
-%endif
 
 BuildRequires:  rust-packaging
 
@@ -37,11 +31,11 @@ BuildArch:      noarch
 
 %description    devel %{_description}
 
-This package contains library source intended for building other packages
+This package contains library source intended for building other packages which
-which use "%{crate}" crate.
+use the "%{crate}" crate.
 
 %files          devel
-%license LICENSE-MIT LICENSE-APACHE
+%license LICENSE-APACHE LICENSE-MIT
 %doc README.md
 %{cargo_registry}/%{crate}-%{version_no_tilde}/
 
@@ -51,8 +45,8 @@ BuildArch:      noarch
 
 %description -n %{name}+default-devel %{_description}
 
-This package contains library source intended for building other packages
+This package contains library source intended for building other packages which
-which use "default" feature of "%{crate}" crate.
+use the "default" feature of the "%{crate}" crate.
 
 %files       -n %{name}+default-devel
 %ghost %{cargo_registry}/%{crate}-%{version_no_tilde}/Cargo.toml