antlr: Turn off CSharp (#8157)

Spack doesn't have a CSharp package, so the only time ANTLR would
succeed is if a system-installed CSharp was available. This disables
CSharp support, which enables building on systems without
system-installed CSharp.

var/spack/repos/builtin/packages/antlr/package.py

@@ -51,6 +51,7 @@ def configure_args(self):
         spec = self.spec
 
         return [
+            '--disable-csharp',
             '--{0}-cxx'.format('enable' if '+cxx' in spec else 'disable'),
             '--{0}-java'.format('enable' if '+java' in spec else 'disable'),
             '--{0}-python'.format('enable' if '+python' in spec else 'disable')