docs: Consistently use minimum Python 3.8

README.md

@@ -56,7 +56,7 @@ for administration of the Hub and its users.
 ### Check prerequisites
 
 - A Linux/Unix based system
-- [Python](https://www.python.org/downloads/) 3.6 or greater
+- [Python](https://www.python.org/downloads/) 3.8 or greater
 - [nodejs/npm](https://www.npmjs.com/)
 
   - If you are using **`conda`**, the nodejs and npm dependencies will be installed for

docs/source/conf.py

@@ -70,6 +70,7 @@ myst_enable_extensions = [
 myst_substitutions = {
     # date example: Dev 07, 2022
     "date": datetime.date.today().strftime("%b %d, %Y").title(),
+    "python_min": "3.8",
     "version": jupyterhub.__version__,
 }
 

docs/source/contributing/setup.md

@@ -12,7 +12,7 @@ development.
 ### Install Python
 
 JupyterHub is written in the [Python](https://python.org) programming language and
-requires you have at least version 3.8 installed locally. If you haven’t
+requires you have at least version {{python_min}} installed locally. If you haven’t
 installed Python before, the recommended way to install it is to use
 [Miniforge](https://github.com/conda-forge/miniforge#download).
 
@@ -59,7 +59,7 @@ a more detailed discussion.
    python -V
    ```
 
-   This should return a version number greater than or equal to 3.8.
+   This should return a version number greater than or equal to {{python_min}}.
 
    ```bash
    npm -v

docs/source/tutorial/quickstart.md

@@ -5,7 +5,7 @@
 Before installing JupyterHub, you will need:
 
 - a Linux/Unix-based system
-- [Python](https://www.python.org/downloads/) 3.6 or greater. An understanding
+- [Python {{python_min}}](https://www.python.org/downloads/) or greater. An understanding
   of using [`pip`](https://pip.pypa.io) or
   [`conda`](https://docs.conda.io/projects/conda/en/latest/user-guide/getting-started.html) for
   installing Python packages is helpful.