Cleanup leftover Nanobox references (#30550)

.nanoignore

@@ -1,19 +0,0 @@
-.DS_Store
-.git/
-.gitignore
-
-.bundle/
-.cache/
-config/deploy/*
-coverage
-docs/
-.env
-log/*.log
-neo4j/
-node_modules/
-public/assets/
-public/system/
-spec/
-tmp/
-.vagrant/
-vendor/bundle/

README.md

@@ -72,7 +72,7 @@ Mastodon acts as an OAuth2 provider, so 3rd party apps can use the REST and Stre
 - **Ruby** 3.1+
 - **Node.js** 18+
 
-The repository includes deployment configurations for **Docker and docker-compose** as well as specific platforms like **Heroku**, **Scalingo**, and **Nanobox**. For Helm charts, reference the [mastodon/chart repository](https://github.com/mastodon/chart). The [**standalone** installation guide](https://docs.joinmastodon.org/admin/install/) is available in the documentation.
+The repository includes deployment configurations for **Docker and docker-compose** as well as specific platforms like **Heroku**, and **Scalingo**. For Helm charts, reference the [mastodon/chart repository](https://github.com/mastodon/chart). The [**standalone** installation guide](https://docs.joinmastodon.org/admin/install/) is available in the documentation.
 
 ## Development