Relax target-lexicon to version 0.12; Fixes RHBZ#1983368

cfg-expr-fix-metadata.diff

@@ -0,0 +1,11 @@
+--- cfg-expr-0.8.0/Cargo.toml	1970-01-01T00:00:00+00:00
++++ cfg-expr-0.8.0/Cargo.toml	2021-07-18T00:12:44.244533+00:00
+@@ -26,7 +26,7 @@
+ version = "1.6"
+ 
+ [dependencies.target-lexicon]
+-version = "0.12.1"
++version = "0.12"
+ optional = true
+ [dev-dependencies.difference]
+ version = "2.0"

rust-cfg-expr.spec

@@ -13,6 +13,9 @@ Summary:        Parser and evaluator for Rust `cfg()` expressions
 License:        MIT or ASL 2.0
 URL:            https://crates.io/crates/cfg-expr
 Source:         %{crates_source}
+# Initial patched metadata
+# * Relax target-lexicon to version 0.12
+Patch0:         cfg-expr-fix-metadata.diff
 
 ExclusiveArch:  %{rust_arches}
 %if %{__cargo_skip_build}