Upgrade to Python 3.12 and PySide 6.6.

.github/workflows/build.yml

@@ -13,11 +13,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
+          python-version: "3.12"
       - name: Install dependencies
         run: |
           sudo apt-get update

Pipfile

@@ -4,13 +4,14 @@ verify_ssl = true
 name = "pypi"
 
 [packages]
-PySide6 = "<6.5"  # 6.5.0 causes fatal Python error. Try 6.5.1 when released.
+PySide6 = "*"
 four-letter-blocks = {editable = true, path = "."}
 beautifulsoup4 = "*"
 scipy = "*"
 
 [dev-packages]
 four-letter-blocks = {editable = true, extras = ["dev"], path = "."}
+mypy = "*"
 
 [requires]
-python_version = "3.10"
+python_version = "3.12"

docs/construct_your_own.md

@@ -109,6 +109,15 @@ it by installing those dependencies like this:
 
     sudo apt-get install freeglut3 freeglut3-dev
 
+Another known bug on Ubuntu 22.04:
+
+>"qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though
+> it was found."
+
+Work around it by installing a dependency like this:
+
+    sudo apt install libxcb-cursor0
+
 ### Splitting Up the Grid
 Start by filling in the title
 and grid. Use the `#` character for black squares. As you type, the bottom of