Revert "Serverless-only availability hack (#5431)"

This reverts commit a996fa3.

Author: pquentin

compiler/src/model/build-model.ts

@@ -102,13 +102,6 @@ export function compileEndpoints (): Record<string, model.Endpoint> {
         }
       })
     }
-
-    // temporary workaround for APIs that are serverless-only
-    // until we can stop depending on rest-api-spec for availability
-    if (api === 'project.tags') {
-      delete map[api].availability.stack
-    }
-
     if (typeof spec.feature_flag === 'string') {
       map[api].availability.stack = { featureFlag: spec.feature_flag }
     }