docs(plugins): deprecate heroku

[sentaur-athena]

DESCRIBE YOUR PR

We're sending emails tomorrow to customers about this deprecation. The docs should reflect the email content.

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.): Sep 24, 2025
• 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

[vercel]

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

Project	Deployment	Preview	Comments	Updated (UTC)
develop-docs	Ready	Preview	Comment	Sep 25, 2025 8:41pm
sentry-docs	Ready	Preview	Comment	Sep 25, 2025 8:41pm

[codecov]

Bundle Report

Changes will decrease total bundle size by 15 bytes (-0.0%) ⬇️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
sentry-docs-client-array-push	10.13MB	-6 bytes (-0.0%) ⬇️
sentry-docs-server-cjs	12.86MB	-9 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%
static/2uNPrZFotELb9qYfHQjAh/_buildManifest.js (New)	684 bytes	684 bytes	100.0% 🚀
static/2uNPrZFotELb9qYfHQjAh/_ssgManifest.js (New)	77 bytes	77 bytes	100.0% 🚀
static/Wq372ncsuq3HDayw8Onrq/_buildManifest.js (Deleted)	-684 bytes	0 bytes	-100.0% 🗑️
static/Wq372ncsuq3HDayw8Onrq/_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	1.78MB	-0.0%
../instrumentation.js	-3 bytes	1.1MB	-0.0%
9523.js	-3 bytes	1.08MB	-0.0%

[coolguyzone]

Thanks for updating, LGTM!