fix(@schematics/angular): correct tsconfig.spec.json include for spec files

Updates the  files in both application and library schematics to specifically include  instead of . This ensures that only test specification files are processed for testing, preventing unintended inclusion of other TypeScript files.

Author: alan-agius4

packages/schematics/angular/application/files/common-files/tsconfig.spec.json.template

@@ -9,6 +9,6 @@
     ]
   },
   "include": [
-    "src/**/*.ts"
+    "src/**/*.spec.ts"
   ]
 }

packages/schematics/angular/library/files/tsconfig.spec.json.template

@@ -9,6 +9,6 @@
     ]
   },
   "include": [
-    "src/**/*.ts"
+    "src/**/*.spec.ts"
   ]
 }