swig: update symlink alias to appease cmake (#43271)

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

@@ -148,7 +148,7 @@ class AutotoolsBuilder(spack.build_systems.autotools.AutotoolsBuilder):
     def create_symlink(self):
         # CMake compatibility: see https://github.com/spack/spack/pull/6240
         with working_dir(self.prefix.bin):
-            os.symlink("swig", "swig{0}".format(self.spec.version.up_to(2)))
+            os.symlink("swig", "swig{0}.0".format(self.spec.version.up_to(1)))
 
     @when(Swig.AUTOCONF_VERSIONS)
     def autoreconf(self, pkg, spec, prefix):