fix: ensure template cache uses unique identifier

lib/loaders/pitcher.js

@@ -72,7 +72,10 @@ module.exports.pitch = function (remainingRequest) {
   // for templates: inject the template compiler & optional cache
   if (query.type === `template`) {
     const cacheLoader = cacheDirectory && cacheIdentifier
-      ? [`cache-loader?${JSON.stringify(options)}`]
+      ? [`cache-loader?${JSON.stringify({
+        cacheDirectory,
+        cacheIdentifier: cacheIdentifier + '-vue-loader-template'
+      })}`]
       : []
     const request = genRequest([
       ...cacheLoader,