docs(js): Update Google Cloud Functions quick start guide

[inventarSarah]

DESCRIBE YOUR PR

This branch contains the updated quick start guide for the Google Cloud Functions SDK.

Closes: #15502

IS YOUR CHANGE URGENT?

Help us prioritize incoming PRs by letting us know when the change needs to go live.

• Urgent deadline (GA date, etc.):
• Other deadline:
• None: Not urgent, can wait up to 1 week+

SLA

• Teamwork makes the dream work, so please add a reviewer to your PRs.
• Please give the docs team up to 1 week to review your PR unless you've added an urgent due date to it.
  Thanks in advance for your help!

PRE-MERGE CHECKLIST

Make sure you've checked the following before merging your changes:

• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

EXTRA RESOURCES

• Sentry Docs contributor guide

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
sentry-docs	Ready	Preview	Comment	Nov 20, 2025 10:02am

1 Skipped Deployment

Project	Deployment	Preview	Comments	Updated (UTC)
develop-docs	Ignored	Preview		Nov 20, 2025 10:02am

[sentry]

Bug: Guide uses v8.x APIs without version info, breaking v7.x users.
_{Severity: MEDIUM | Confidence: Medium}

🔍 Detailed Analysis

The updated guide exclusively uses v8.x APIs for @sentry/google-cloud-serverless without providing any version information. Users on SDK v7.x or earlier following this guide will encounter code examples that fail at runtime because the APIs (e.g., Sentry.init() directly, Sentry.wrapHttpFunction()) do not exist in their SDK version. This creates a significant functional and logical implication, leading to broken code for users not on the latest major version.

💡 Suggested Fix

Add a clear version alert or note indicating that the guide's code examples are for @sentry/google-cloud-serverless v8.x and above. Consider providing separate documentation paths or version toggles if v7.x support is still intended.

🤖 Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: docs/platforms/javascript/guides/gcp-functions/index.mdx#L13-L15

Potential issue: The updated guide exclusively uses v8.x APIs for
`@sentry/google-cloud-serverless` without providing any version information. Users on
SDK v7.x or earlier following this guide will encounter code examples that fail at
runtime because the APIs (e.g., `Sentry.init()` directly, `Sentry.wrapHttpFunction()`)
do not exist in their SDK version. This creates a significant functional and logical
implication, leading to broken code for users not on the latest major version.

_{Did we get this right? 👍 / 👎 to inform future reviews.
Reference_id: 2837083}

[codecov]

Bundle Report

Changes will increase total bundle size by 453 bytes (0.0%) ⬆️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
sentry-docs-server-cjs	12.81MB	459 bytes (0.0%) ⬆️
sentry-docs-client-array-push	10.17MB	-6 bytes (-0.0%) ⬇️

Affected Assets, Files, and Routes:

view changes for bundle: sentry-docs-client-array-push

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
static/chunks/pages/_app-*.js	-3 bytes	882.71kB	-0.0%
static/chunks/8321-*.js	-3 bytes	425.87kB	-0.0%
server/middleware-*.js	-6.46kB	1.0kB	-86.59%
server/middleware-*.js	6.46kB	7.46kB	645.5% ⚠️
static/GVnOVgrsUCYQH8OmKOXV1/_buildManifest.js (New)	684 bytes	684 bytes	100.0% 🚀
static/GVnOVgrsUCYQH8OmKOXV1/_ssgManifest.js (New)	77 bytes	77 bytes	100.0% 🚀
static/cGiM7GIklNRXDOxuIaODY/_buildManifest.js (Deleted)	-684 bytes	0 bytes	-100.0% 🗑️
static/cGiM7GIklNRXDOxuIaODY/_ssgManifest.js (Deleted)	-77 bytes	0 bytes	-100.0% 🗑️

view changes for bundle: sentry-docs-server-cjs

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
1729.js	-3 bytes	1.74MB	-0.0%
../instrumentation.js	-3 bytes	1.07MB	-0.0%
9523.js	-3 bytes	1.04MB	-0.0%
../app/[[...path]]/page.js.nft.json	156 bytes	832.72kB	0.02%
../app/platform-redirect/page.js.nft.json	156 bytes	832.63kB	0.02%
../app/sitemap.xml/route.js.nft.json	156 bytes	829.86kB	0.02%