docs: remove the 1M challenge admonitions (#2248)

Author: TC-MO

sources/academy/build-and-publish/actor-ideas/what_software_an_actor_can_be.md

@@ -158,14 +158,6 @@ The [Actor ideas](https://apify.com/ideas) page is where you can find inspiratio
 
 ### Browse and claim ideas
 
-:::note Join The Apify $1M Challenge
-
-Build and publish new tools on Apify and have multiple chances to win big prizes.
-
-[Join the challenge now.](https://apify.com/challenge)
-
-:::
-
 1. _Visit_ [apify.com/ideas](https://apify.com/ideas) to find ideas that interest you. Look for ideas that align with your skills.
 
 1. _Select an Actor idea_: Review the details and requirements. Check the status—if it's marked **Open to develop**, you can start building.

sources/platform/actors/development/index.md

@@ -10,14 +10,6 @@ slug: /actors/development
 
 ---
 
-:::note Join The Apify $1M Challenge
-
-Build and publish new tools on Apify and have multiple chances to win big prizes.
-
-[Join the challenge now.](https://apify.com/challenge)
-
-:::
-
 This section will guide you through the whole story of [Actor](../index.mdx) development.
 
 You can follow chapters sequentially from [Quick start](/platform/actors/development/quick-start), where you learn how to create your first Actor in just a few minutes, through the more technical sections describing the whole Actor model, up to the [Performance](/sources/platform/actors/development/performance.md) section, where you learn how to fine-tune your Actor to get the most out of the Apify platform.