Address comments

.devcontainer/post-create-command.sh

@@ -7,6 +7,10 @@ if ! git remote | grep -q "fork"; then
     git remote add fork https://github.com/${GIT_USER}/flask
 fi
 
+# Create and activate a virtualenv
+python3 -m venv .venv
+. .venv/bin/activate
+
 # Upgrade pip and setuptools
 python -m pip install --upgrade pip setuptools
 

.devcontainer/welcome-message.txt

@@ -2,6 +2,6 @@
 
 🛠️  Your environment is setup with all the required dependencies and your fork has been added as a remote.
 
-🚀  To start coding:
-    - wait for the "postCreateCommand" to finish setting things up
-    - run `git checkout -b your-branch-name origin/{main-or-latest-release}` to start working on a new feature or bug fix.
+🚀  To start coding, wait for the "postCreateCommand" to finish setting things up, then:
+    - run `. .venv/bin/activate` to activate your virtualenv
+    - run `git checkout -b your-branch-name origin/{main-or-latest-release}` to start working on a new feature or bug fix

CHANGES.rst

@@ -6,8 +6,6 @@ Unreleased
 -   Use modern packaging metadata with ``pyproject.toml`` instead of ``setup.cfg``.
     :pr:`4947`
 -   Ensure subdomains are applied with nested blueprints. :issue:`4834`
--   Automatically setup project and install dependencies with the
-    ``.devcontainer/devcontainer.json``. :issue:`4965`
 
 
 Version 2.2.3