SL updates for coalesce (#6253)

this pr updates some SL docs and removes the 'preview' flag for two
features:

- custom calendar
- python sdk

website/docs/docs/build/metricflow-time-spine.md

@@ -298,7 +298,7 @@ and date_hour < dateadd(day, 30, current_timestamp())
 </File>
 
 
-## Custom calendar <Lifecycle status="Preview"/>
+## Custom calendar
 
 <VersionBlock lastVersion="1.8">
 

website/docs/docs/dbt-cloud-apis/sl-api-overview.md

@@ -43,7 +43,7 @@ plan="dbt Cloud Team or Enterprise"
     icon="dbt-bit"/>
 
 <Card
-    title="Python SDK (Preview)"
+    title="Python SDK"
     body="Use the Python SDK to interact with the dbt Semantic Layer using Python."
     link="/docs/dbt-cloud-apis/sl-python"
     icon="dbt-bit"/>

website/docs/docs/dbt-cloud-apis/sl-python-sdk.md

@@ -7,7 +7,6 @@ keywords: [dbt Cloud, API, dbt Semantic Layer, python, sdk]
 sidebar_label: "Python SDK"
 ---
 
-# Python SDK <Lifecycle status="Preview"/>
 The [`dbt-sl-sdk` Python software development kit](https://github.com/dbt-labs/semantic-layer-sdk-python) (SDK) is a Python library that provides you with easy access to the dbt Semantic Layer with Python. It allows developers to interact with the dbt Semantic Layer APIs and query metrics and dimensions in downstream tools. 
 
 ## Installation