Release v4.3-beta1 (#19172)

* Draft changelog for v4.3 release

* Add release notes summary & nav link

* Docs cleanup

* Update Python dependencies

* Update static assets

* Revert errant change to schema

* Fix minimum PostgreSQL version

* Misc cleanup

* Correct issue numbers in change log

docs/configuration/system.md

@@ -14,6 +14,8 @@ BASE_PATH = 'netbox/'
 
 ## DATABASE_ROUTERS
 
+!!! info "This parameter was introduced in NetBox v4.3."
+
 Default: `[]` (empty list)
 
 An iterable of [database routers](https://docs.djangoproject.com/en/stable/topics/db/multi-db/) to use for automatically selecting the appropriate database(s) for a query. This is useful only when [multiple databases](./required-parameters.md#databases) have been configured.
@@ -172,6 +174,8 @@ The file path to the location where media files (such as image attachments) are
 
 ## PROXY_ROUTERS
 
+!!! info "This parameter was introduced in NetBox v4.3."
+
 Default: `["utilities.proxy.DefaultProxyRouter"]`
 
 A list of Python classes responsible for determining which proxy server(s) to use for outbound HTTP requests. Each item in the list can be the class itself or the dotted path to the class.