docs(dev-infra): Update development environment docs (#14585)

<!-- Use this checklist to make sure your PR is ready for merge. You may
delete any sections you don't need. -->

## DESCRIBE YOUR PR
This changes the workflow for getting people onboarded onto their sentry
development environments to use the new `devservices serve` and
devservices modes for enabling ingestion.

## 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.): <!-- ENTER DATE HERE -->
- [ ] Other deadline: <!-- ENTER DATE HERE -->
- [x] 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](https://github.com/orgs/getsentry/teams/docs)

## EXTRA RESOURCES

- [Sentry Docs contributor guide](https://docs.sentry.io/contributing/)

Author: hubertdeng123

develop-docs/development-infrastructure/environment/index.mdx

@@ -34,12 +34,9 @@ devservices up
 After that, you can start the development server inside the `sentry` folder:
 
 ```shell
-sentry devserver --workers
+devservices serve
 ```
 
-If you are developing for aesthetics only and do not rely on the async workers, you can omit the `--workers` flag in order
-to use fewer system resources.
-
 Access it at [http://dev.getsentry.net:8000](http://dev.getsentry.net:8000) (you'll have to wait a bit for webpack to finish).
 A superuser account should have been created for you during bootstrap - `[email protected]` with password `admin`.
 You can create other users with `sentry createuser`.
@@ -86,8 +83,8 @@ After the server is running we can visit the dev server using `https` at port `:
 <Link to="/relay/">Relay</Link> and the ingest workers are not started by default. Follow the instructions below to start them so you can send events to your dev environment Sentry instance:
 
 - Set `SENTRY_USE_RELAY = True` in `~/.sentry/sentry.conf.py`.
-- Run `devservices up` to start the services Relay needs. (like for example Kafka)
-- (Re-)Start your devserver with the `--ingest` flag (e.g. `sentry devserver --workers --ingest`). This will start the Relay container and all related services alongside your devserver.
+- Run `devservices up --mode ingest` to start the services Relay needs. (like for example Kafka)
+- Start your devserver (e.g. `devservices serve`).
 
 ## Running the Getsentry Development Server
 
@@ -108,7 +105,7 @@ devservices up
 After that, you can start the development server inside the `getsentry` folder:
 
 ```shell
-getsentry devserver --workers
+devservices serve
 ```
 
 **Note**: You **cannot** have both sentry and getsentry devserver running at the same time.
@@ -123,7 +120,7 @@ by `dev.py` if it exists.
 To enable the ingest workers, follow the steps described <Link to="#ingestion-pipeline-relay">here</Link> and run
 
 ```shell
-getsentry devserver --workers --ingest
+devservices serve
 ```
 
 ## Running siloed instances
@@ -134,10 +131,10 @@ The devserver command supports `--silo` option that lets you create siloed insta
 
 ```shell
 # Start control silo servers
-sentry devserver --silo=control --celery-beat --workers
+devservices serve --silo=control --celery-beat
 
 # Start region silo servers
-sentry devserver --silo=region --celery-beat --workers --ingest
+devservices serve --silo=region --celery-beat
 ```
 
 Siloed servers have the following port assignments: