build(docs-infra): fixed i18n broken stackblitz example (#42001)

This commit fixes the broken stackblitz example of i18n.

Closes #41838.

PR Close #42001

aio/content/examples/i18n/stackblitz.json

@@ -8,5 +8,6 @@
       "**/*.xlf"
     ],
     "file": "src/app/app.component.ts", 
-    "tags": ["Angular", "i18n", "internationalization"]
+    "tags": ["Angular", "i18n", "internationalization"],
+    "devDependencies": ["@angular/compiler-cli", "typescript"]
 }

aio/content/examples/testing/specs.stackblitz.json

@@ -19,5 +19,6 @@
     "src/**/*.spec.ts"
   ],
   "main": "src/index-specs.html",
-  "tags": ["testing"]
+  "tags": ["testing"],
+  "devDependencies": ["jasmine-core", "jasmine-marbles"]
 }

aio/content/examples/testing/stackblitz.json

@@ -14,5 +14,6 @@
 
     "!src/**/*.spec.ts"
   ],
-  "tags": ["testing"]
+  "tags": ["testing"],
+  "devDependencies": ["jasmine-core", "jasmine-marbles"]
 }

aio/tools/stackblitz-builder/builder.js

@@ -48,7 +48,7 @@ class StackblitzBuilder {
 
     // Add unit test packages from devDependencies for unit test examples
     const devDependencies = packageJson.devDependencies;
-    ['jasmine-core', 'jasmine-marbles'].forEach(dep => exampleDependencies[dep] = devDependencies[dep]);
+    (config.devDependencies || []).forEach(dep => exampleDependencies[dep] = devDependencies[dep]);
 
     postData.dependencies = JSON.stringify(exampleDependencies);
   }