Deprecate Metrics APIs

[stephanie-anderson]

Description

Since we'll discontinue our current version of Metrics, we need to deprecate our APIs for Metrics / DDM in all SDKs

The message should read as follows:

This API is deprecated and will be removed in the next major release. Sentry will reject all metrics sent after October 7, 2024. Learn more: https://sentry.zendesk.com/hc/en-us/articles/26369339769883-Upcoming-API-Changes-to-Metrics

Why should we be doing this?

So our users won't try to send in Metrics, it would be frustrating.

Why now?

The Metrics Beta will end on October 3, 2024, comms were going out September 4th, docs are being changed September 5th.

RFC

No response

Slack-Channel

#proj-ddm

Notion Document(s)

No response

Stakeholder(s)

Ale & Armin

Team(s)

Mobile, Web Backend, Web Frontend

SDKs

## SDKs
- [ ] https://github.com/getsentry/sentry-cli/issues/2150
- [ ] https://github.com/getsentry/sentry-python/issues/3502
- [ ] https://github.com/getsentry/sentry-dotnet/issues/3597
- [x] PHP SDK https://github.com/getsentry/sentry-php/pull/1786
- [x] Laravel SDK https://github.com/getsentry/sentry-laravel/pull/951
- [x] Symfony SDK (depends on PHP)
- [x] Go SDK https://github.com/getsentry/sentry-go/pull/914
- [x] ~~Native SDK~~ (never shipped)
- [x] https://github.com/getsentry/sentry-javascript/issues/14264
- [x] Java SDK https://github.com/getsentry/sentry-java/pull/3774
- [x] Android SDK https://github.com/getsentry/sentry-java/pull/3774
- [x] Apple/Cocoa SDK https://github.com/getsentry/sentry-cocoa/pull/4406
- [x] ~~Capacitor SDK~~
- [x] ~~Cordova SDK~~
- [x] Dart SDK https://github.com/getsentry/sentry-dart/pull/2312
- [x] Flutter SDK (depends on Dart)
- [x] Kotlin Multiplatform SDK (depends on native SDKs and was never configured in the KMP layer)
- [x] React Native SDK deprecated by JS update https://github.com/getsentry/sentry-react-native/pull/4236
- [x] Electron SDK
- [x] Ruby SDK https://github.com/getsentry/sentry-ruby/pull/2539
- [x] Rust SDK https://github.com/getsentry/sentry-rust/issues/736