Disable tests on riscv64

Solves:
[..]
[2 of 2] Compiling Main
<no location info>: error:
    Couldn't find a target code interpreter. Try with -fexternal-interpreter
error: Bad exit status from /var/tmp/rpm-tmp.iin36B (%build)
    Bad exit status from /var/tmp/rpm-tmp.iin36B (%build)
RPM build errors:
Child return code was: 1
[..]

Signed-off-by: David Abdurachmanov <davidlt@rivosinc.com>

ghc-th-lift-instances.spec

@@ -4,11 +4,15 @@
 %global pkg_name th-lift-instances
 %global pkgver %{pkg_name}-%{version}
 
+%ifnarch riscv64
 %bcond_without tests
+%else
+%bcond_with tests
+%endif
 
 Name:           ghc-%{pkg_name}
 Version:        0.1.20
-Release:        %autorelease
+Release:        %autorelease -e 0.riscv64
 Summary:        Lift instances for template-haskell for common data types
 
 License:        BSD-3-Clause