Migrate all samples to firebase-functions v7 (#1227)

* use the test build of functions v7

* use 7.0.0

* feat: Migrate Node-1st-gen samples from functions.config to params (#1229)

* feat: Migrate Node-1st-gen samples from functions.config to params

Migrates all Cloud Functions for Firebase samples in the Node-1st-gen folder that use the functions.config API to the new params API.

This includes:
- Replacing `functions.config()` with `defineString` for non-sensitive data and `defineSecret` for sensitive data.
- Updating function definitions with `runWith({secrets: [...]})` where necessary.
- Moving API client initializations from the global scope into function handlers to ensure that parameter values are available at runtime.
- Updating all relevant README.md files and code comments to reflect the new configuration methods.

* feat(Node-1st-gen): Migrate functions.config to params

Migrates all 1st-gen Node.js samples from the deprecated functions.config API to the new params API.

- Updates all instances of functions.config() to use defineString() or defineSecret().
- Moves client initializations that depend on params into the function bodies.
- Updates variable names to lowerCamelCase to follow the recommended style.
- Updates all relevant README.md files to reflect the new configuration method using .env files and firebase functions:secrets:set.
- Verifies that all 1st-gen samples compile successfully after the changes.

* feat(Node-1st-gen): Migrate functions.config to params

Migrates all 1st-gen Node.js samples from the deprecated functions.config API to the new params API.

- Updates all instances of functions.config() to use defineString() or defineSecret().
- Moves client initializations that depend on params into the function bodies.
- Updates variable names to lowerCamelCase to follow the recommended style.
- Updates all relevant README.md files to reflect the new configuration method using .env files and firebase functions:secrets:set.
- Verifies that all 1st-gen samples compile successfully after the changes.
- Corrects the `runWith` secrets configuration to pass the secret objects directly.
- Refactors all client initializations to use the `onInit` hook.
- Fixes the `google-sheet-sync` trigger.
- Fixes inconsistent naming in `okta-auth` and `testlab-to-slack`.
- Fixes inefficient `cors` initialization in `okta-auth`.

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Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

---------

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: jhuleatt

Node-1st-gen/assistant-say-number/functions/package.json

@@ -4,7 +4,7 @@
   "dependencies": {
     "actions-on-google": "^2.14.0",
     "firebase-admin": "^13.0.2",
-    "firebase-functions": "^6.3.0"
+    "firebase-functions": "7.0.0"
   },
   "devDependencies": {
     "eslint": "^8.57.1",