Pin API Extractor for template package (Azure#21522)

* Pin API Extractor for template package

Author: praveenkuttappan

common/config/rush/pnpm-lock.yaml

@@ -95,7 +95,7 @@
     "@azure/test-utils": "^1.0.0",
     "@azure-tools/test-credential": "~1.0.0",
     "@azure-tools/test-recorder": "^2.0.0",
-    "@microsoft/api-extractor": "^7.18.11",
+    "@microsoft/api-extractor": "7.18.11",
     "@types/chai": "^4.1.6",
     "@types/mocha": "^7.0.2",
     "@types/node": "^12.0.0",