refactor: revert the workaround out of !1256

#1256

Author: mfranzke

packages/core/src/lib/pattern_engines.js

@@ -103,14 +103,6 @@ const PatternEngines = Object.create({
     const enginesInConfig = findEnginesInConfig(patternLabConfig);
 
     if (enginesInConfig) {
-      // Quick fix until we've removed @pattern-lab/engine-mustache, starting with https://github.com/pattern-lab/patternlab-node/issues/1239 & https://github.com/pattern-lab/patternlab-node/pull/1455
-      // @TODO: Remove after removing @pattern-lab/engine-mustache dependency
-      enginesInConfig.mustache = enginesInConfig.mustache || {};
-      enginesInConfig.mustache.package =
-        enginesInConfig.mustache.package || '@pattern-lab/engine-mustache';
-      enginesInConfig.mustache.extensions =
-        enginesInConfig.mustache.extensions || 'mustache';
-
       // Try loading each of the configured pattern engines
       // eslint-disable-next-line guard-for-in
       for (const name in enginesInConfig) {