chore(medusa-test-utils): create declaration file (#6858)

**What**
- Fixes tsconfig to ensure a declaration file is included in the build.

**Why**
- Ensure tsserver can understand things from medusa-test-utils
- Get rid of "Could not find a declaration file for module" warning in editors.

.changeset/polite-shoes-matter.md

@@ -0,0 +1,6 @@
+---
+"@medusajs/medusa": patch
+"medusa-test-utils": patch
+---
+
+chore(medusa-test-utils): create declaration file

packages/medusa-test-utils/tsconfig.json

@@ -4,7 +4,7 @@
     "target": "es5",
     "outDir": "./dist",
     "esModuleInterop": true,
-    "declaration": false,
+    "declaration": true,
     "module": "commonjs",
     "moduleResolution": "node",
     "emitDecoratorMetadata": true,

packages/medusa/package.json

@@ -34,6 +34,7 @@
     "cross-env": "^5.2.1",
     "jest": "^25.5.4",
     "medusa-interfaces": "^1.3.9",
+    "medusa-test-utils": "^1.1.43",
     "rimraf": "^5.0.1",
     "supertest": "^4.0.2",
     "ts-jest": "^25.5.1",
@@ -84,7 +85,6 @@
     "lodash": "^4.17.21",
     "medusa-core-utils": "^1.2.1",
     "medusa-telemetry": "^0.0.17",
-    "medusa-test-utils": "^1.1.43",
     "morgan": "^1.9.1",
     "multer": "^1.4.5-lts.1",
     "node-schedule": "^2.1.1",