blast-plus package: remove --with-64 on ARM. (#11877)

This configure option is not supported on ARM

var/spack/repos/builtin/packages/blast-plus/package.py

@@ -102,10 +102,11 @@ def configure_args(self):
             '--with-bin-release',
             '--without-debug',
             '--with-mt',
-            '--with-64',
             '--without-boost',
         ]
 
+        if 'aarch64' not in spec.architecture.target.lower():
+            config_args.append('--with-64')
         if '+static' in spec:
             config_args.append('--with-static')
             # FIXME