chore(headless): add commerce entry to quantic use case mappings (#4678)

Adding the current browser commerce headless distribution as a static
resource in Salesforce is not compatible with the LWC environment.

To enable Coveo Headless Commerce in Salesforce, a commerce use case
needs to be added to the quanticUseCaseEntries to support this
functionality effectively.

#4677 

https://coveord.atlassian.net/browse/KIT-3741

packages/headless/esbuild.mjs

@@ -41,6 +41,7 @@ const quanticUseCaseEntries = {
   recommendation: 'src/recommendation.index.ts',
   'case-assist': 'src/case-assist.index.ts',
   insight: 'src/insight.index.ts',
+  commerce: 'src/commerce.index.ts',
 };
 
 function getUmdGlobalName(useCase) {