Skip doctests due to problems with LLVM 14 on armv7hl and LLVM 12 on i686

* https://bugzilla.redhat.com/show_bug.cgi?id=2086106
* https://bugzilla.redhat.com/show_bug.cgi?id=2020861

rust-encoding_rs.spec

@@ -207,7 +207,8 @@ use the "serde" feature of the "%{crate}" crate.
 
 %if %{with check}
 %check
-%cargo_test
+# * doctests fail to compile on armv7hl with LLVM 14 and on i686 with LLVM 12
+%cargo_test -- --lib
 %endif
 
 %changelog