chore: update release notes for RS 9.0.0 (#21102)

# Overview

Collapsing the former RS 8.9.0 release notes into existing RS 9.0.0
release notes.

## Test Plan and Hands on Testing



## Changelog



## Review requests

Are these known issues still accurate? 

## Risk assessment

low.

Author: emilyburghardt

api/release-notes.md

@@ -13,6 +13,7 @@ Welcome to the v9.0.0 release of the Opentrons robot software! This release incl
 ### New Features
 
 - Use the `set_empty()` method to load an empty tip rack on the deck.
+- Use Opentrons Flex 20 µL pipette tips in your protocols. The tips are fully compatible with [liquid class](https://docs.opentrons.com/python-api/liquid-classes/) commands and with Flex 1- and 8-Channel (1-50 µL range) and 96-Channel (1-200 µL range) pipettes.
 
 ### Feature Improvements
 
@@ -22,13 +23,11 @@ Welcome to the v9.0.0 release of the Opentrons robot software! This release incl
 - Change the position to dispose of tips in any trash bin, including a non-default trash bin, with the `drop_tip()` method.
 - Liquid class transfers are optimized to prevent unnecessary movements to the top of a well before proceeding.
 
----
-
-## Opentrons Robot Software Changes in 8.9.0
+### Bug Fixes
 
-Welcome to the v8.9.0 release of the Opentrons robot software!
+- This release fixes the Flex boot issue on some network configurations.
 
-This release includes support for Opentrons Flex 20 µL pipette tips. The tips are fully compatible with [liquid class](https://docs.opentrons.com/python-api/liquid-classes/) commands and with Flex 1- and 8-Channel (1-50 µL range) and 96-Channel (1-200 µL range) pipettes.
+---
 
 ## Opentrons Robot Software Changes in 8.8.1
 

app-shell/build/release-notes.md

@@ -21,6 +21,10 @@ Welcome to the v9.0.0 release of the Opentrons App! This release includes protoc
 
 ### Improvements
 
+- Quick transfer protocols now include the same features as any other Flex protocol:
+  - Go to the Protocols tab on the touchscreen to start a quick transfer.
+  - Find completed quick transfers in the Protocols tab.
+  - Pin a quick transfer protocol to find it easily.
 - Enable the Flex or OT-2's built-in camera for additional settings:
   - Adjust image and video settings like zoom, brightness, contrast, and saturation.
   - Preview an image of the Flex or OT-2's deck when customizing camera controls.
@@ -39,16 +43,6 @@ Welcome to the v9.0.0 release of the Opentrons App! This release includes protoc
 
 ---
 
-## Opentrons App Changes in 8.9.0
-
-Welcome to the v8.9.0 release of the Opentrons App! This release updates quick transfer protocols with the same features as any other Flex protocol:
-
-- Go to the Protocols tab on the touchscreen to start a quick transfer.
-- Find completed quick transfers in the Protocols tab.
-- Pin a quick transfer protocol to find it easily.
-
----
-
 ## Opentrons App Changes in 8.8.1
 
 There are no changes to the Opentrons App in v8.8.1.